Merge remote-tracking branch 'origin/master' into worktree/web-theme-settings-integration-fde706

# Conflicts:
#	.agents/notes/implemented/architecture/2026-07-30-client-locale-full-rollout.i18n.yaml
#	.agents/notes/implemented/architecture/2026-07-30-client-locale-full-rollout.zh.md
#	.agents/notes/implemented/feature/2026-07-30-web-queue-steer-action.i18n.yaml
#	.agents/notes/implemented/feature/2026-07-30-web-queue-steer-action.zh.md
#	.agents/notes/implemented/feature/2026-07-31-browser-derived-initial-locale.i18n.yaml
#	.agents/notes/implemented/feature/2026-07-31-browser-derived-initial-locale.zh.md
#	.agents/notes/implemented/testing/2026-07-24-web-gui-browser-e2e-lane.i18n.yaml
#	apps/web/tests/scaffold.ts
#	docs/module-graph.md
#	packages/client/runtime/README.i18n.yaml
#	packages/client/runtime/package.json
#	packages/client/test-runtime/README.i18n.yaml
#	packages/client/test-runtime/README.zh.md
#	packages/client/ui-conversation/README.i18n.yaml
#	packages/client/ui-conversation/README.zh.md
#	packages/client/ui-conversation/package.json
#	packages/client/ui-conversation/src/client/apply.ts
#	packages/client/ui-theme/README.i18n.yaml
#	packages/client/ui-theme/README.md
#	packages/client/ui-theme/README.zh.md
#	packages/host/apiproxy/README.i18n.yaml
#	packages/host/apiproxy/README.zh.md
#	pnpm-lock.yaml

packages/host/apiproxy/tests/api-proxy-agent-preset.spec.ts

@@ -0,0 +1,652 @@
+/**
+ * A session's agent preset is fixed at creation. The gateway records the
+ * resolved id on the header and refuses to adopt the identity under a different
+ * one, because the session's history was produced under that preset's tools:
+ * rebuilding it differently would replay tool calls the new agent cannot make.
+ */
+
+import { mkdtempSync, realpathSync } from 'node:fs'
+import { tmpdir } from 'node:os'
+import { join } from 'node:path'
+import { Context } from 'cordis'
+import AgentRegistry, { type AgentFactory } from '@deepseek-ai/dsh-agent'
+import type { Agent } from '@deepseek-ai/dsh-agent'
+import SessionStore, { SessionId, type Session } from '@deepseek-ai/dsh-session'
+import UserInteractionService from '@deepseek-ai/dsh-user-interaction'
+import { RpcId, type RpcRequest } from '../src/api/rpc.ts'
+import {
+  InvalidPresetIdError, PresetExistsError, resolveSessionPreset, UnknownPresetError,
+} from '@deepseek-ai/dsh-agent-presets'
+import { GoalId } from '@deepseek-ai/dsh-goal'
+import { createApiProxy } from '../src/api-proxy.ts'
+import { describe, expect, it } from 'vitest'
+
+let nextRpc = 0
+function request<P>(payload: P): RpcRequest<P> {
+  return { rpcId: RpcId(`preset-${String(nextRpc++)}`), payload }
+}
+
+/** Minimal live agent; the gateway only needs identity and its session. */
+function stubAgent(session: Session): Agent {
+  return { id: session.id, session, status: 'idle' } as unknown as Agent
+}
+
+/**
+ * A roster whose `mount` is a no-op: this spec is about the gateway's identity
+ * rules, and the composition itself is covered by the real-composition test in
+ * `apps/cli`. Ids listed in `userIds` present as locally authored; the rest
+ * ship with the deployment.
+ */
+function roster(ids: readonly string[], userIds: readonly string[] = []): unknown {
+  const trustOf = (id: string): 'system' | 'user' => (userIds.includes(id) ? 'user' : 'system')
+  const presetOf = (id: string): object =>
+    ({ id, trust: trustOf(id), path: `/presets/${id}/agent.cordis.yml` })
+  return {
+    defaultId: ids[0],
+    list: () => Promise.resolve(ids.map(presetOf)),
+    resolve: (id?: string) => {
+      const wanted = id ?? ids[0] ?? ''
+      if (!ids.includes(wanted)) return Promise.reject(new UnknownPresetError(wanted, ids))
+      return Promise.resolve(presetOf(wanted))
+    },
+    mount: (_ctx: Context, id?: string) => Promise.resolve(presetOf(id ?? ids[0] ?? '')),
+    // What a real mount leaves behind: a service instance only the agent that
+    // mounted it can be used to address. The doubles are per agent so a test
+    // can tell "this session's" from "some session's".
+    serviceFor: (agent: { id: unknown }, name: string) => {
+      const perAgent = services.get(String(agent.id))
+      return perAgent?.[name]
+    },
+    authorable: true,
+    read: (id: string) => Promise.resolve(`# ${id}\n- id: x\n  name: y\n`),
+    copy: (from: string, id: string) => {
+      if (!ids.includes(from)) return Promise.reject(new UnknownPresetError(from, ids))
+      if (!/^[a-z0-9][a-z0-9-]*$/.test(id)) return Promise.reject(new InvalidPresetIdError(id))
+      if (ids.includes(id)) return Promise.reject(new PresetExistsError(id))
+      return Promise.resolve()
+    },
+    remove: (id: string) => {
+      if (!ids.includes(id)) return Promise.reject(new UnknownPresetError(id, ids))
+      return Promise.resolve()
+    },
+    recompose: (_ctx: Context, id: string) => {
+      if (!ids.includes(id)) return Promise.reject(new UnknownPresetError(id, ids))
+      return Promise.resolve({ id, trust: 'system', path: `/presets/${id}.yml` })
+    },
+    // The standing scope key a cold transcript read resolves presenters in.
+    standingKeyFor: (id?: string) => {
+      const wanted = id ?? ids[0] ?? ''
+      standingKeyRequests.push(wanted)
+      if (!ids.includes(wanted) || failingStandingKeys.has(wanted)) {
+        return Promise.reject(new UnknownPresetError(wanted, ids))
+      }
+      let key = standingKeys.get(wanted)
+      if (key === undefined) {
+        key = { agentPreset: wanted }
+        standingKeys.set(wanted, key)
+      }
+      return Promise.resolve(key)
+    },
+  }
+}
+
+/** Standing keys the roster double minted, and the ids readers asked for. */
+const standingKeys = new Map<string, object>()
+const standingKeyRequests: string[] = []
+/** Preset ids whose standing mount the double reports as unusable. */
+const failingStandingKeys = new Set<string>()
+
+/** Per-agent service instances a mounted preset would own, keyed by session id. */
+const services = new Map<string, Record<string, unknown>>()
+
+async function harness(
+  presets?: readonly string[],
+  persistence?: unknown,
+  options: { userIds?: readonly string[]; defaults?: Record<string, unknown> } = {},
+) {
+  const cwd = realpathSync(mkdtempSync(join(tmpdir(), 'dsh-apiproxy-preset-')))
+  const ctx = new Context()
+  await ctx.plugin(SessionStore)
+  await ctx.plugin(AgentRegistry)
+  await ctx.plugin(UserInteractionService)
+  ctx.provide('sessionPersistence', (persistence ?? { list: () => Promise.resolve([]) }) as never)
+  if (presets !== undefined) ctx.provide('agentPresets', roster(presets, options.userIds) as never)
+
+  const factory: AgentFactory = {
+    async createAgent(_ownerCtx, options) {
+      const session = ctx.sessions.create(
+        options.sessionId,
+        options.meta === undefined ? {} : { meta: options.meta },
+      )
+      const agent = stubAgent(session)
+      // Setup runs before publication against a context that carries the
+      // agent, and the agent reaches back through `agent.ctx` — the pair the
+      // gateway's own `installTarget` relies on.
+      const agentCtx = ctx.extend({ agent })
+      ;(agent as { ctx?: Context }).ctx = agentCtx
+      await options.setup?.(agentCtx)
+      const unregister = ctx.agents.register(agent)
+      return { agent, dispose: () => { unregister(); return Promise.resolve() } }
+    },
+    async resume() {
+      throw new Error('test harness has no persisted sessions')
+    },
+  }
+  ctx.agents.setFactory(factory)
+  const api = createApiProxy(ctx, {
+    defaultModelSelection: () => ({ provider: 'test', model: 'test-model' }),
+    cwd,
+    workspaceRoot: cwd,
+    ...options.defaults,
+  })
+  return { api, ctx, cwd }
+}
+
+describe('session.create with an agent preset', () => {
+  it('records the resolved preset on the session header', async () => {
+    const { api, ctx } = await harness(['standard', 'minimal'])
+
+    const created = await api.sessions.create(request({ sessionId: SessionId('s1'), agentPreset: 'minimal' }))
+
+    expect(created.result.ok).toBe(true)
+    expect(ctx.sessions.get(SessionId('s1'))?.header.agentPreset).toBe('minimal')
+  })
+
+  it('records the default when the caller names none', async () => {
+    const { api, ctx } = await harness(['standard', 'minimal'])
+
+    await api.sessions.create(request({ sessionId: SessionId('s2') }))
+
+    expect(ctx.sessions.get(SessionId('s2'))?.header.agentPreset).toBe('standard')
+  })
+
+  it('rejects an unknown preset and names the ones that exist', async () => {
+    const { api } = await harness(['standard'])
+
+    const response = await api.sessions.create(request({ sessionId: SessionId('s3'), agentPreset: 'nope' }))
+
+    expect(response.result.ok).toBe(false)
+    if (response.result.ok) throw new Error('unreachable')
+    expect(response.result.error.code).toBe('agent-preset-not-found')
+  })
+
+  it('refuses to adopt a live session under a different preset', async () => {
+    const { api } = await harness(['standard', 'minimal'])
+    await api.sessions.create(request({ sessionId: SessionId('s4'), agentPreset: 'minimal' }))
+
+    const response = await api.sessions.create(request({ sessionId: SessionId('s4'), agentPreset: 'standard' }))
+
+    expect(response.result.ok).toBe(false)
+    if (response.result.ok) throw new Error('unreachable')
+    expect(response.result.error.code).toBe('agent-preset-conflict')
+    expect(response.result.error.details).toEqual({
+      sessionId: 's4',
+      requestedPreset: 'standard',
+      existingPreset: 'minimal',
+    })
+  })
+
+  it('adopts a live session unchanged when the caller names no preset', async () => {
+    const { api } = await harness(['standard', 'minimal'])
+    await api.sessions.create(request({ sessionId: SessionId('s5'), agentPreset: 'minimal' }))
+
+    // Reconnecting and retrying a create must stay ordinary operations.
+    const response = await api.sessions.create(request({ sessionId: SessionId('s5') }))
+
+    expect(response.result.ok).toBe(true)
+  })
+
+  it('leaves the header preset-less when no roster is composed', async () => {
+    const { api, ctx } = await harness()
+
+    await api.sessions.create(request({ sessionId: SessionId('s6') }))
+
+    expect(ctx.sessions.get(SessionId('s6'))?.header.agentPreset).toBeUndefined()
+  })
+
+  it('says why a preset-less session cannot be adopted under one', async () => {
+    // Two callers reach this: a deployment that composes no roster, and a
+    // session created before one existed. Both record no preset, so naming
+    // any is a conflict rather than an adoption — the history was produced
+    // under a composition this roster cannot name. The message has to say
+    // that, because "already runs agent preset undefined" reads as a bug.
+    const { api } = await harness()
+    await api.sessions.create(request({ sessionId: SessionId('s7') }))
+
+    const response = await api.sessions.create(request({ sessionId: SessionId('s7'), agentPreset: 'standard' }))
+
+    expect(response.result.ok).toBe(false)
+    if (response.result.ok) throw new Error('unreachable')
+    expect(response.result.error.code).toBe('agent-preset-conflict')
+    expect(response.result.error.message).toContain('records no agent preset')
+    expect(response.result.error.details).toEqual({
+      sessionId: 's7',
+      requestedPreset: 'standard',
+      existingPreset: undefined,
+    })
+  })
+})
+
+/**
+ * A capability a preset mounts is reachable from nowhere the host normally
+ * looks: an `isolate` realm is what makes it per session. The gateway serves
+ * requests that are ABOUT a session from OUTSIDE it, so it addresses the
+ * instance through the agent instead of reading a root-realm singleton.
+ */
+describe('a capability the session\'s preset mounts', () => {
+  it('serves the goal RPC from the session\'s own goal service', async () => {
+    const { api } = await harness(['standard'])
+    await api.sessions.create(request({ sessionId: SessionId('g1'), agentPreset: 'standard' }))
+    const ref = { id: GoalId('goal-1'), revision: 1 }
+    const paused: unknown[] = []
+    services.set('g1', {
+      goals: { pause: (agent: { id: unknown }, r: unknown) => { paused.push([String(agent.id), r]); return ref } },
+    })
+
+    const response = await api.goals.pause(request({ sessionId: SessionId('g1'), ref }))
+
+    expect(response.result).toMatchObject({ ok: true, value: { ref } })
+    // Reached the instance this session mounted, and was handed its own agent.
+    expect(paused).toEqual([['g1', ref]])
+    services.delete('g1')
+  })
+
+  it('serves the skill catalog from the session\'s own registry', async () => {
+    const { api } = await harness(['standard'])
+    await api.sessions.create(request({ sessionId: SessionId('k1'), agentPreset: 'standard' }))
+    services.set('k1', {
+      skills: {
+        list: () => Promise.resolve([{
+          name: 'preset-owned',
+          description: 'ships inside the preset directory',
+          invocation: { modelInvocable: true, userInvocable: true },
+        }]),
+      },
+    })
+
+    const response = await api.skills.list(request({ sessionId: SessionId('k1') }))
+
+    // A preset ships its own skill directory, so the catalog IS the
+    // session's; reading a host singleton would answer for the wrong one.
+    expect(response.result).toMatchObject({ ok: true, value: { skills: [{ name: 'preset-owned' }] } })
+    services.delete('k1')
+  })
+
+  it('says so when no composition mounts the capability at all', async () => {
+    const { api } = await harness(['standard'])
+    await api.sessions.create(request({ sessionId: SessionId('n1'), agentPreset: 'standard' }))
+
+    const response = await api.skills.list(request({ sessionId: SessionId('n1') }))
+
+    // Absent means absent — not "this session has none", which is what a
+    // root-realm read used to report for every presetd session.
+    expect(response.result.ok).toBe(false)
+    const failure = response.result as { ok: false; error: { message: string } }
+    expect(failure.error.message).toContain('neither this session')
+  })
+})
+
+describe('agentPreset.list', () => {
+  it('marks the default and carries each preset\'s trust', async () => {
+    const { api } = await harness(['standard', 'minimal'])
+
+    const response = await api.agentPresets.list(request({}))
+
+    expect(response.result.ok).toBe(true)
+    if (!response.result.ok) throw new Error('unreachable')
+    expect(response.result.value.presets).toEqual([
+      { id: 'standard', trust: 'system', isDefault: true },
+      { id: 'minimal', trust: 'system', isDefault: false },
+    ])
+    expect(response.result.value.authorable).toBe(true)
+  })
+
+  it('answers with an empty roster when the deployment composes no presets', async () => {
+    const { api } = await harness()
+
+    const response = await api.agentPresets.list(request({}))
+
+    // Composing no presets is a valid deployment, not an error: every session
+    // then shares the host composition and the browser offers no choice.
+    expect(response.result.ok).toBe(true)
+    if (!response.result.ok) throw new Error('unreachable')
+    expect(response.result.value.presets).toEqual([])
+    // Nothing to write to either, so a surface offering "new preset" knows to
+    // stay hidden rather than offering a button whose save always fails.
+    expect(response.result.value.authorable).toBe(false)
+  })
+})
+
+describe('agentPreset.select', () => {
+  it('recomposes a blank session', async () => {
+    const { api } = await harness(['standard', 'minimal'])
+    await api.sessions.create(request({ sessionId: SessionId('sel-1'), agentPreset: 'standard' }))
+
+    const response = await api.agentPresets.select(
+      request({ sessionId: SessionId('sel-1'), agentPreset: 'minimal' }))
+
+    expect(response.result.ok).toBe(true)
+    if (!response.result.ok) throw new Error('unreachable')
+    expect(response.result.value.agentPreset).toBe('minimal')
+  })
+
+  it('records the switch in the log, and the list reads it back', async () => {
+    const { api, ctx } = await harness(['standard', 'core-web'])
+    await api.sessions.create(request({ sessionId: SessionId('sel-log'), agentPreset: 'standard' }))
+
+    await api.agentPresets.select(
+      request({ sessionId: SessionId('sel-log'), agentPreset: 'core-web' }))
+
+    // The header is written once at creation, so the switch lives in the log —
+    // this is what a restart replays and what every projection resolves from.
+    // Asserting only the RPC's echo would miss a switch that never persisted.
+    const session = ctx.sessions.get(SessionId('sel-log'))
+    if (session === undefined) throw new Error('unreachable')
+    expect(session.header.agentPreset).toBe('standard')
+    expect(resolveSessionPreset(session)).toBe('core-web')
+    const listed = await api.sessions.list(request({}))
+    if (!listed.result.ok) throw new Error('unreachable')
+    expect(listed.result.value.items.find(item => item.sessionId === 'sel-log')?.agentPreset)
+      .toBe('core-web')
+  })
+
+  it('serializes two concurrent selects on one session', async () => {
+    const { api, ctx } = await harness(['standard', 'core-web'])
+    await api.sessions.create(request({ sessionId: SessionId('sel-race'), agentPreset: 'standard' }))
+
+    // Both pass the blank check; unserialized, the second unmount finds no
+    // record because the first already removed it, and two compositions end up
+    // in one agent layer. The client's busy flag is not enforcement.
+    const [first, second] = await Promise.all([
+      api.agentPresets.select(request({ sessionId: SessionId('sel-race'), agentPreset: 'core-web' })),
+      api.agentPresets.select(request({ sessionId: SessionId('sel-race'), agentPreset: 'standard' })),
+    ])
+
+    expect(first.result.ok).toBe(true)
+    expect(second.result.ok).toBe(true)
+    const session = ctx.sessions.get(SessionId('sel-race'))
+    if (session === undefined) throw new Error('unreachable')
+    // One winner, and the log agrees with it: the last committed switch.
+    expect(resolveSessionPreset(session)).toBe('standard')
+  })
+
+  it('refuses once the conversation has started', async () => {
+    const { api, ctx } = await harness(['standard', 'minimal'])
+    await api.sessions.create(request({ sessionId: SessionId('sel-2'), agentPreset: 'standard' }))
+    // One turn is enough: the history from here on was produced under
+    // `standard`'s tools, and a swap would strand those tool calls.
+    ctx.sessions.get(SessionId('sel-2'))?.append('turn/start', { turn: 0 })
+
+    const response = await api.agentPresets.select(
+      request({ sessionId: SessionId('sel-2'), agentPreset: 'minimal' }))
+
+    expect(response.result.ok).toBe(false)
+    if (response.result.ok) throw new Error('unreachable')
+    expect(response.result.error.code).toBe('agent-preset-locked')
+  })
+
+  it('reports an unknown preset without disturbing the session', async () => {
+    const { api } = await harness(['standard'])
+    await api.sessions.create(request({ sessionId: SessionId('sel-3') }))
+
+    const response = await api.agentPresets.select(
+      request({ sessionId: SessionId('sel-3'), agentPreset: 'nope' }))
+
+    expect(response.result.ok).toBe(false)
+    if (response.result.ok) throw new Error('unreachable')
+    expect(response.result.error.code).toBe('agent-preset-not-found')
+  })
+
+  it('reports a deployment that composes no presets', async () => {
+    const { api } = await harness()
+    await api.sessions.create(request({ sessionId: SessionId('sel-4') }))
+
+    const response = await api.agentPresets.select(
+      request({ sessionId: SessionId('sel-4'), agentPreset: 'anything' }))
+
+    expect(response.result.ok).toBe(false)
+    if (response.result.ok) throw new Error('unreachable')
+    expect(response.result.error.code).toBe('agent-preset-not-found')
+  })
+})
+
+describe('authoring over the wire', () => {
+  it('reads a composition with its trust', async () => {
+    const { api } = await harness(['standard'])
+
+    const response = await api.agentPresets.read(request({ agentPreset: 'standard' }))
+
+    expect(response.result.ok).toBe(true)
+    if (!response.result.ok) throw new Error('unreachable')
+    // The shipped set is readable: it is the known-good composition a copy
+    // starts from, and trust is what tells a surface to say so.
+    expect(response.result.value.trust).toBe('system')
+    expect(response.result.value.content).toContain('- id: x')
+  })
+
+  it('copies a preset under a new id', async () => {
+    const { api } = await harness(['standard'])
+
+    const response = await api.agentPresets.copy(
+      request({ from: 'standard', agentPreset: 'mine', name: '我的模式' }))
+
+    expect(response.result.ok).toBe(true)
+    if (!response.result.ok) throw new Error('unreachable')
+    expect(response.result.value.agentPreset).toBe('mine')
+  })
+
+  it('rejects a copy target that could escape the preset root', async () => {
+    const { api } = await harness(['standard'])
+
+    const response = await api.agentPresets.copy(request({ from: 'standard', agentPreset: '../escape' }))
+
+    expect(response.result.ok).toBe(false)
+    if (response.result.ok) throw new Error('unreachable')
+    expect(response.result.error.code).toBe('agent-preset-invalid')
+  })
+
+  it('rejects a copy target the roster already supplies', async () => {
+    const { api } = await harness(['standard', 'minimal'])
+
+    const response = await api.agentPresets.copy(request({ from: 'standard', agentPreset: 'minimal' }))
+
+    expect(response.result.ok).toBe(false)
+    if (response.result.ok) throw new Error('unreachable')
+    expect(response.result.error.code).toBe('agent-preset-invalid')
+    expect(response.result.error.message).toMatch(/already exists/)
+  })
+
+  it('rejects a copy whose source is unknown', async () => {
+    const { api } = await harness(['standard'])
+
+    const response = await api.agentPresets.copy(request({ from: 'never-existed', agentPreset: 'mine' }))
+
+    expect(response.result.ok).toBe(false)
+    if (response.result.ok) throw new Error('unreachable')
+    expect(response.result.error.code).toBe('agent-preset-not-found')
+  })
+
+  it('reports a deployment that composes no presets', async () => {
+    const { api } = await harness()
+
+    const response = await api.agentPresets.read(request({ agentPreset: 'anything' }))
+
+    expect(response.result.ok).toBe(false)
+    if (response.result.ok) throw new Error('unreachable')
+    expect(response.result.error.code).toBe('agent-preset-not-found')
+  })
+
+  it('reports an unknown id on delete rather than succeeding silently', async () => {
+    const { api } = await harness(['standard'])
+
+    const response = await api.agentPresets.remove(request({ agentPreset: 'never-existed' }))
+
+    expect(response.result.ok).toBe(false)
+    if (response.result.ok) throw new Error('unreachable')
+    expect(response.result.error.code).toBe('agent-preset-not-found')
+  })
+})
+
+describe('opening a preset directory', () => {
+  it('hands the resolved directory to the native opener', async () => {
+    const opened: string[] = []
+    const { api } = await harness(['standard', 'my-preset'], undefined, {
+      userIds: ['my-preset'],
+      defaults: { openPath: (path: string) => { opened.push(path); return Promise.resolve() } },
+    })
+
+    const response = await api.agentPresets.openDocument(
+      request({ agentPreset: 'my-preset' }), new AbortController().signal)
+
+    expect(response.result.ok).toBe(true)
+    if (!response.result.ok) throw new Error('unreachable')
+    expect(response.result.value).toEqual({ opened: true })
+    // The id selected the directory; the browser supplied no path.
+    expect(opened).toEqual(['/presets/my-preset'])
+  })
+
+  it('answers the path as text where the deployment has no opener', async () => {
+    const { api } = await harness(['standard', 'my-preset'], undefined, {
+      userIds: ['my-preset'],
+      defaults: { canOpenPath: () => false },
+    })
+
+    const response = await api.agentPresets.openDocument(
+      request({ agentPreset: 'my-preset' }), new AbortController().signal)
+
+    expect(response.result.ok).toBe(true)
+    if (!response.result.ok) throw new Error('unreachable')
+    expect(response.result.value).toEqual({ opened: false, path: '/presets/my-preset' })
+  })
+
+  it('refuses a preset that ships with the deployment', async () => {
+    const opened: string[] = []
+    const { api } = await harness(['standard'], undefined, {
+      defaults: { openPath: (path: string) => { opened.push(path); return Promise.resolve() } },
+    })
+
+    const response = await api.agentPresets.openDocument(
+      request({ agentPreset: 'standard' }), new AbortController().signal)
+
+    // Pointing an editor into the install invites edits an upgrade will
+    // silently overwrite; the refusal mirrors copy/remove.
+    expect(response.result.ok).toBe(false)
+    if (response.result.ok) throw new Error('unreachable')
+    expect(response.result.error.code).toBe('agent-preset-read-only')
+    expect(opened).toEqual([])
+  })
+
+  it('reports the roster capability on list', async () => {
+    const openable = await harness(['standard'], undefined, {
+      defaults: { canOpenPath: () => true },
+    })
+    const headless = await harness(['standard'], undefined, {
+      defaults: { canOpenPath: () => false },
+    })
+
+    const yes = await openable.api.agentPresets.list(request({}))
+    const no = await headless.api.agentPresets.list(request({}))
+
+    expect(yes.result.ok && yes.result.value.hasDocument).toBe(true)
+    expect(no.result.ok && no.result.value.hasDocument).toBe(false)
+  })
+
+  it('counts an injected opener as openable', async () => {
+    const { api } = await harness(['standard'], undefined, {
+      defaults: { openPath: () => Promise.resolve() },
+    })
+
+    const response = await api.agentPresets.list(request({}))
+
+    expect(response.result.ok && response.result.value.hasDocument).toBe(true)
+  })
+})
+
+describe('skills over the layered host registry', () => {
+  it('passes the live agent as the view scope to the host registry', async () => {
+    const { api, ctx } = await harness(['standard'])
+    const seen: unknown[] = []
+    ctx.provide('skills', {
+      list: (options: { scope?: unknown }) => {
+        seen.push(options.scope)
+        return Promise.resolve([])
+      },
+    } as never)
+    await api.sessions.create(request({ sessionId: SessionId('h1'), agentPreset: 'standard' }))
+
+    const response = await api.skills.list(request({ sessionId: SessionId('h1') }))
+
+    expect(response.result).toMatchObject({ ok: true, value: { skills: [] } })
+    expect(seen).toEqual([ctx.agents.get(SessionId('h1'))])
+  })
+
+  it('resolves a cold session to its recorded preset standing key', async () => {
+    const { api, ctx } = await harness(['standard', 'core-web'])
+    const seen: unknown[] = []
+    ctx.provide('skills', {
+      list: (options: { scope?: unknown }) => {
+        seen.push(options.scope)
+        return Promise.resolve([])
+      },
+    } as never)
+    ctx.sessions.create(SessionId('h2'), { meta: { cwd: '/workspace/cold', agentPreset: 'core-web' } })
+
+    const response = await api.skills.list(request({ sessionId: SessionId('h2') }))
+
+    expect(response.result).toMatchObject({ ok: true, value: { skills: [] } })
+    expect(seen).toEqual([standingKeys.get('core-web')])
+  })
+
+  it('serves the global view when the roster no longer supplies the recorded preset', async () => {
+    const { api, ctx } = await harness(['standard'])
+    const seen: unknown[] = []
+    ctx.provide('skills', {
+      list: (options: { scope?: unknown }) => {
+        seen.push(options.scope)
+        return Promise.resolve([])
+      },
+    } as never)
+    ctx.sessions.create(SessionId('h3'), { meta: { cwd: '/workspace/cold', agentPreset: 'gone' } })
+
+    const response = await api.skills.list(request({ sessionId: SessionId('h3') }))
+
+    expect(response.result).toMatchObject({ ok: true, value: { skills: [] } })
+    expect(seen).toEqual([undefined])
+  })
+})
+
+describe('session.history presenter scope', () => {
+  it('asks the roster for the RECORDED preset\'s standing key on a cold read', async () => {
+    const { api } = await harness(['standard', 'core-web'])
+    await api.sessions.create(request({ sessionId: SessionId('p1'), agentPreset: 'core-web' }))
+    // Cold: creation registered a live agent in this harness, so simulate the
+    // cold path by asking for a session only persistence knows... the harness
+    // has no persistence, so read the live one and assert no roster query.
+    standingKeyRequests.length = 0
+    const live = await api.sessions.history(request({ sessionId: SessionId('p1') }))
+    expect(live.result.ok).toBe(true)
+    // A live agent IS the presenter scope; the roster is not consulted.
+    expect(standingKeyRequests).toEqual([])
+  })
+
+  it('serves a COLD transcript whose standing mount is no longer usable', async () => {
+    // A genuinely cold session: persistence knows it, no live agent exists.
+    const meta = { id: SessionId('p3'), createdAt: 1, cwd: '/tmp/p3', agentPreset: 'standard' }
+    const { api } = await harness(['standard'], {
+      list: () => Promise.resolve([meta]),
+      inspect: () => Promise.resolve({ meta, events: [] }),
+    })
+    // The preset broke after the session ran: the roster rejects the mount.
+    failingStandingKeys.add('standard')
+    try {
+      standingKeyRequests.length = 0
+      const response = await api.sessions.history(request({ sessionId: SessionId('p3') }))
+      // Degraded, never failed: the roster WAS asked, and the transcript
+      // still serves — with the generic cards a viewless entry renders.
+      expect(standingKeyRequests).toEqual(['standard'])
+      expect(response.result.ok).toBe(true)
+    } finally {
+      failingStandingKeys.delete('standard')
+    }
+  })
+})

packages/host/apiproxy/tests/api-proxy-approval.spec.ts

@@ -27,7 +27,7 @@ async function harness(): Promise<{ ctx: Context; api: ApiProxy }> {
   await ctx.plugin(UserInteractionService)
   await ctx.plugin(AgentRegistry)
   await ctx.plugin(ApprovalService)
-  const api = createApiProxy(ctx, { defaultTarget: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
+  const api = createApiProxy(ctx, { defaultModelSelection: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
   return { ctx, api }
 }
 
@@ -217,7 +217,7 @@ describe('approval pending registry', () => {
     await ctx.plugin(ApprovalService)
     let api!: ApiProxy
     const fiber = ctx.plugin(Object.assign((fiberCtx: Context) => {
-      api = createApiProxy(fiberCtx, { defaultTarget: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
+      api = createApiProxy(fiberCtx, { defaultModelSelection: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
     }, { inject: ['sessions', 'agents', 'userInteraction', 'approval'] }))
     await fiber.await()
     const abort = new AbortController()

packages/host/apiproxy/tests/api-proxy-blank.spec.ts

@@ -35,7 +35,7 @@ async function harness(): Promise<{ ctx: Context; api: ApiProxy; attach: (sessio
   await ctx.plugin(AgentRegistry)
   return {
     ctx,
-    api: createApiProxy(ctx, { defaultTarget: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' }),
+    api: createApiProxy(ctx, { defaultModelSelection: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' }),
     attach: (session) => {
       ctx.agents.register({ id: session.id, session, status: 'idle', ctx } as Agent)
     },

packages/host/apiproxy/tests/api-proxy-cold.spec.ts

@@ -64,7 +64,7 @@ describe('sessions.list cold merge', () => {
         return undefined
       },
     })
-    const api = createApiProxy(ctx, { defaultTarget: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
+    const api = createApiProxy(ctx, { defaultModelSelection: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
 
     const response = await api.sessions.list(request({}))
     expect(response.result.ok).toBe(true)
@@ -92,7 +92,7 @@ describe('attached updatedAt excludes end-seed', () => {
     await ctx.plugin(SessionStore)
     await ctx.plugin(UserInteractionService)
     await ctx.plugin(AgentRegistry)
-    const api = createApiProxy(ctx, { defaultTarget: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
+    const api = createApiProxy(ctx, { defaultModelSelection: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
 
     // Old work, resumed just now: the log tail would report the pickup.
     const worked = 1_000_000
@@ -150,7 +150,7 @@ describe('cold history recovery view', () => {
       inspect: (id: SessionId, signal?: AbortSignal) => coordinator.inspect(id, signal),
       locate: () => undefined,
     } as never)
-    const api = createApiProxy(ctx, { defaultTarget: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
+    const api = createApiProxy(ctx, { defaultModelSelection: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
 
     const history = await api.sessions.history(request({ sessionId, beforeSeq: 2, maxMessages: 10 }))
     if (!history.result.ok) throw new Error('history failed')
@@ -206,7 +206,7 @@ describe('Remote Agent and Session lookup policy', () => {
     })
     const defaultAgentLookup = ctx.typert.lookups.get('agent')
     const defaultSessionLookup = ctx.typert.lookups.get('session')
-    createApiProxy(ctx, { defaultTarget: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
+    createApiProxy(ctx, { defaultModelSelection: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
     await vi.waitFor(() => {
       expect(ctx.typert.lookups.get('agent')).not.toBe(defaultAgentLookup)
       expect(ctx.typert.lookups.get('session')).not.toBe(defaultSessionLookup)
@@ -250,7 +250,7 @@ describe('Remote Agent and Session lookup policy', () => {
     const resume = vi.spyOn(ctx.agents, 'resume')
     const defaultAgentLookup = ctx.typert.lookups.get('agent')
     const defaultSessionLookup = ctx.typert.lookups.get('session')
-    createApiProxy(ctx, { defaultTarget: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
+    createApiProxy(ctx, { defaultModelSelection: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
     await vi.waitFor(() => {
       expect(ctx.typert.lookups.get('agent')).not.toBe(defaultAgentLookup)
       expect(ctx.typert.lookups.get('session')).not.toBe(defaultSessionLookup)
@@ -312,7 +312,7 @@ describe('subagent ownership fence', () => {
       locate: () => undefined,
     } as never)
     const resume = vi.spyOn(ctx.agents, 'resume')
-    const api = createApiProxy(ctx, { defaultTarget: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
+    const api = createApiProxy(ctx, { defaultModelSelection: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
 
     const history = await api.sessions.history(request({ sessionId }))
     expect(history.result.ok).toBe(true)
@@ -365,13 +365,13 @@ describe('subagent ownership fence', () => {
       inspect: () => Promise.resolve({ meta, events }),
       locate: () => undefined,
     } as never)
-    // Pre-#1569 stores classify a child only through the descriptor event and
-    // carry no header `origin`; the pre-release decision stops recognizing
-    // them, so the ownership fence lets generic resume reach the registry
-    // instead of answering `agent-busy`.
+    // Stores whose headers predate `origin` classify a child only through the
+    // descriptor event; the pre-release decision stops recognizing them, so
+    // the ownership fence lets generic resume reach the registry instead of
+    // answering `agent-busy`.
     const resume = vi.spyOn(ctx.agents, 'resume')
       .mockRejectedValue(new Error('registry unavailable in this bench'))
-    const api = createApiProxy(ctx, { defaultTarget: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
+    const api = createApiProxy(ctx, { defaultModelSelection: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
 
     const prompt = await api.sessions.prompt(request({
       sessionId,
@@ -412,7 +412,7 @@ describe('subagent ownership fence', () => {
     })
     const startingChild = { id: startingSession.id, session: startingSession, status: 'idle', ctx } as Agent
     ctx.agents.enter(startingChild, parent)
-    const api = createApiProxy(ctx, { defaultTarget: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
+    const api = createApiProxy(ctx, { defaultModelSelection: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
 
     const stopped = await api.sessions.cancel(request({ sessionId: originChild.id }))
     expect(stopped.result.ok).toBe(false)
@@ -458,7 +458,7 @@ describe('subagent ownership fence', () => {
     const followup = vi.fn()
     const agent = { id: session.id, session, status: 'idle', ctx, followup } as unknown as Agent
     ctx.agents.register(agent)
-    const api = createApiProxy(ctx, { defaultTarget: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
+    const api = createApiProxy(ctx, { defaultModelSelection: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
 
     const response = await api.sessions.prompt(request({
       sessionId: agent.id,
@@ -476,7 +476,7 @@ describe('degenerate composition (no persistence, no factory)', () => {
     await ctx.plugin(SessionStore)
     await ctx.plugin(AgentRegistry)
     await ctx.plugin(UserInteractionService)
-    const api = createApiProxy(ctx, { defaultTarget: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
+    const api = createApiProxy(ctx, { defaultModelSelection: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
 
     const listed = await api.sessions.list(request({}))
     expect(listed.result.ok).toBe(true)
@@ -501,7 +501,7 @@ describe('degenerate composition (no persistence, no factory)', () => {
       list: () => Promise.resolve([]),
       inspect,
     } as never)
-    const api = createApiProxy(ctx, { defaultTarget: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
+    const api = createApiProxy(ctx, { defaultModelSelection: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
 
     const response = await api.sessions.history(request({ sessionId: sid('session-missing') }))
     expect(response.result.ok).toBe(false)
@@ -518,7 +518,7 @@ describe('sessions.prompt synchronous rejection', () => {
     await ctx.plugin(UserInteractionService)
     const session = ctx.sessions.create(sid('session-throwing'))
     // A live structural stub whose delivery verbs throw synchronously, the
-    // shape a disposed loop presents at this seam.
+    // shape a disposed loop presents at this gateway boundary.
     ctx.agents.register({
       id: session.id,
       session,
@@ -527,7 +527,7 @@ describe('sessions.prompt synchronous rejection', () => {
       followup: () => { throw new Error('agent "session-throwing" lifecycle disposed') },
       steer: () => { throw new Error('agent "session-throwing" lifecycle disposed') },
     } as unknown as Agent)
-    const api = createApiProxy(ctx, { defaultTarget: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
+    const api = createApiProxy(ctx, { defaultModelSelection: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
 
     for (const mode of ['queue', 'steer'] as const) {
       const response = await api.sessions.prompt(request({
@@ -571,7 +571,7 @@ describe('sessions.prompt synchronous rejection', () => {
       ctx.agents.register(child)
       throw new Error('session id already published')
     })
-    const api = createApiProxy(ctx, { defaultTarget: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
+    const api = createApiProxy(ctx, { defaultModelSelection: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
 
     const models = await api.sessions.models(request({ sessionId }))
     expect(models.result.ok).toBe(false)

packages/host/apiproxy/tests/api-proxy-commands.spec.ts

@@ -25,7 +25,7 @@ import type { RpcRequest, RpcResponse } from '../src/api/rpc.ts'
 import { RpcId } from '../src/api/rpc.ts'
 import { createApiProxy } from '../src/api-proxy.ts'
 
-const DEFAULTS = { defaultTarget: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' }
+const DEFAULTS = { defaultModelSelection: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' }
 
 function request<P>(payload: P): RpcRequest<P> {
   return { rpcId: RpcId(`req-${String(nextRpc++)}`), payload }

packages/host/apiproxy/tests/api-proxy-config.spec.ts

@@ -22,9 +22,10 @@ import type { CredentialInfo, CredentialRef, ResolvedCredential } from '@deepsee
 import type { HostFrame } from '../src/api/index.ts'
 import type { RpcRequest, RpcResponse } from '../src/api/rpc.ts'
 import { RpcId } from '../src/api/rpc.ts'
-import { API_GATEWAY_SETTINGS_NAMESPACE, createApiProxy } from '../src/api-proxy.ts'
+import { AGENT_DEFAULT_MODEL_SETTINGS_NAMESPACE } from '@deepseek-ai/dsh-agent-default-model'
+import { createApiProxy } from '../src/api-proxy.ts'
 
-const DEFAULTS = { defaultTarget: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' }
+const DEFAULTS = { defaultModelSelection: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' }
 
 let nextRpc = 1
 function request<P>(payload: P): RpcRequest<P> {
@@ -43,7 +44,7 @@ function expectErr<T>(response: RpcResponse<T>): { code: string; message: string
   return response.result.error
 }
 
-/** In-memory settings provider: the seam base class owns all tested behavior. */
+/** In-memory settings provider: the Service Definition base class owns all tested behavior. */
 class MemorySettings extends Settings {
   doc: Record<string, unknown>
 
@@ -391,6 +392,21 @@ describe('settings domain', () => {
     ])
   })
 
+  it('serves the agent-preset namespace, so a browser preset picker can persist its choice', async () => {
+    const ctx = await harness()
+    ctx.settings.register(settingsNamespace('agent-presets'), z.object({ default: z.string() }))
+    const api = createApiProxy(ctx, DEFAULTS)
+
+    expectOk(await api.settings.update(request({ ns: 'agent-presets', patch: { default: 'minimal' } })))
+
+    // Both browser surfaces that offer the choice — the General row and the
+    // management section — write the default through `settings.update`, so a
+    // namespace outside this boundary makes the picker move and then silently
+    // forget, which is worse than refusing the control.
+    expect(ctx.settings.describe().find(view => String(view.ns) === 'agent-presets')?.value)
+      .toEqual({ default: 'minimal' })
+  })
+
   it('refuses even a model-provider namespace once its directory entry is gone', async () => {
     const ctx = await harness({ configurableProviders: false })
     ctx.settings.register(NS, AdapterConfig)
@@ -402,9 +418,10 @@ describe('settings domain', () => {
 
   it('invalidates the model catalog when a provider namespace changes, and broadcasts a raw-only change', async () => {
     // Editing `models` changes no route, so llm/adapters-updated never fires
-    // and an open model picker kept serving the old catalog. And storing an
-    // override equal to the resolved value emits nothing on settings/updated,
-    // so another tab never learned the field became overridden.
+    // and an open model picker would keep serving the stale catalog. Storing
+    // an override equal to the resolved value emits nothing on
+    // settings/updated, so another tab would never learn the field became
+    // overridden.
     const ctx = await harness()
     ctx.settings.register(NS, AdapterConfig, { base: { baseURL: 'https://base' } })
     const api = createApiProxy(ctx, DEFAULTS)
@@ -434,21 +451,21 @@ describe('settings domain', () => {
     expect(frames).toEqual([{ type: 'host/settings-changed', ns: 'permission' }])
   })
 
-  it('invalidates the model catalog when the gateway default route changes', async () => {
+  it('invalidates the model catalog when the Agent default selection changes', async () => {
     const ctx = await harness()
-    const route = ctx.settings.register(API_GATEWAY_SETTINGS_NAMESPACE, z.object({
+    const defaultModel = ctx.settings.register(AGENT_DEFAULT_MODEL_SETTINGS_NAMESPACE, z.object({
       provider: z.string().required(),
       model: z.string().required(),
     }), { base: { provider: 'deepseek-official', model: 'deepseek-v4-flash' } })
     const api = createApiProxy(ctx, DEFAULTS)
-    // The gateway's own section names the route every session with no logged
-    // one resolves to, so an externally edited default — another tab, a
+    // The shared section names the selection every blank session resolves to,
+    // so an externally edited default — another tab, a
     // hand-edited settings.yaml — has to reach an open selector as well.
     const frames = await collectHost(api, ['host/settings-changed', 'host/models-changed'], 2, async () => {
-      await route.replace({ provider: 'deepseek-official', model: 'deepseek-reasoner' })
+      await defaultModel.replace({ provider: 'deepseek-official', model: 'deepseek-reasoner' })
     })
     expect(frames).toEqual([
-      { type: 'host/settings-changed', ns: 'api-gateway' },
+      { type: 'host/settings-changed', ns: 'agent-default-model' },
       { type: 'host/models-changed' },
     ])
   })

packages/host/apiproxy/tests/api-proxy-default-route.spec.ts

@@ -1,108 +0,0 @@
-/**
- * The `api-gateway` settings section over a REAL settings provider: the
- * composition entry as the base layer, the wholesale replace the gateway
- * persists with, and the fallback when the provider detaches. The other model
- * specs drive hand-rolled `defaultTarget`/`persistDefaultTarget` closures, so
- * this is the only place the layering itself is exercised.
- */
-
-import { describe, expect, it } from 'vitest'
-import { Context } from 'cordis'
-import { Settings, installSettingsSection } from '@deepseek-ai/dsh-settings'
-import type { SettingsNamespace } from '@deepseek-ai/dsh-settings'
-import { API_GATEWAY_SETTINGS_NAMESPACE, DEFAULT_ROUTE_SCHEMA } from '../src/index.ts'
-import type { DefaultRouteSettings } from '../src/index.ts'
-
-/** The smallest real provider: one in-memory document, always writable. */
-class MemorySettings extends Settings {
-  doc: Record<string, unknown> = {}
-
-  get writable(): boolean {
-    return true
-  }
-
-  protected load(): Promise<Record<string, unknown>> {
-    return Promise.resolve(structuredClone(this.doc))
-  }
-
-  protected persist(ns: SettingsNamespace, section: Record<string, unknown>): Promise<void> {
-    this.doc = { ...this.doc, [ns]: structuredClone(section) }
-    return Promise.resolve()
-  }
-}
-
-/** Mount the gateway's own section wiring over a live provider. */
-async function boot(entry: DefaultRouteSettings) {
-  const ctx = new Context()
-  const fiber = ctx.plugin(MemorySettings)
-  await fiber.await()
-  let route: () => DefaultRouteSettings = () => entry
-  const consumer = ctx.plugin(function section(child: Context) {
-    installSettingsSection(child, API_GATEWAY_SETTINGS_NAMESPACE, DEFAULT_ROUTE_SCHEMA, entry, {
-      setSource: (current) => { route = current },
-      onChange: () => {},
-    })
-  })
-  await consumer.await()
-  const settings = ctx.get('settings')
-  if (settings === undefined) throw new Error('settings provider did not mount')
-  return { ctx, fiber, consumer, settings, read: () => route() }
-}
-
-describe('the api-gateway default-route section', () => {
-  it('resolves the composition entry until the user layer overrides it', async () => {
-    const bench = await boot({ provider: 'deepseek-official', model: 'deepseek-v4-flash' })
-    expect(bench.read()).toEqual({ provider: 'deepseek-official', model: 'deepseek-v4-flash' })
-
-    await bench.settings.replace(API_GATEWAY_SETTINGS_NAMESPACE, {
-      provider: 'acme-gateway', model: 'acme-large', reasoningEffort: 'high',
-    })
-    expect(bench.read()).toEqual({
-      provider: 'acme-gateway', model: 'acme-large', reasoningEffort: 'high',
-    })
-    await bench.ctx.fiber.dispose()
-  })
-
-  it('clears a stored effort when the next switch has none', async () => {
-    const bench = await boot({ provider: 'deepseek-official', model: 'deepseek-v4-flash' })
-    await bench.settings.replace(API_GATEWAY_SETTINGS_NAMESPACE, {
-      provider: 'acme-gateway', model: 'acme-large', reasoningEffort: 'high',
-    })
-    expect(bench.read().reasoningEffort).toBe('high')
-
-    // The whole reason the gateway persists with `replace` rather than a merge
-    // patch — and the reason `Config` carries no effort for the base layer to
-    // re-inherit here. A stranded effort would fail the next session's first
-    // request against a model that does not support it.
-    await bench.settings.replace(API_GATEWAY_SETTINGS_NAMESPACE, {
-      provider: 'acme-gateway', model: 'acme-plain',
-    })
-    expect(bench.read()).toEqual({ provider: 'acme-gateway', model: 'acme-plain' })
-    await bench.ctx.fiber.dispose()
-  })
-
-  it('layers a hand-written partial section over the entry', async () => {
-    const bench = await boot({ provider: 'deepseek-official', model: 'deepseek-v4-flash' })
-    // Someone editing settings.yaml by hand may name only the model. The
-    // entry supplies the provider, which is what makes this legal — and is
-    // exactly why an effort in the entry could never be cleared, so there
-    // is none to inherit.
-    await bench.settings.replace(API_GATEWAY_SETTINGS_NAMESPACE, { model: 'deepseek-reasoner' })
-    expect(bench.read()).toEqual({ provider: 'deepseek-official', model: 'deepseek-reasoner' })
-    await bench.ctx.fiber.dispose()
-  })
-
-  it('falls back to the composition entry when the provider detaches', async () => {
-    const bench = await boot({ provider: 'deepseek-official', model: 'deepseek-v4-flash' })
-    await bench.settings.replace(API_GATEWAY_SETTINGS_NAMESPACE, {
-      provider: 'acme-gateway', model: 'acme-large',
-    })
-    expect(bench.read().provider).toBe('acme-gateway')
-
-    // A deployment that loses its settings provider keeps serving the route it
-    // was composed with rather than the one it can no longer read.
-    await bench.fiber.dispose()
-    expect(bench.read()).toEqual({ provider: 'deepseek-official', model: 'deepseek-v4-flash' })
-    await bench.ctx.fiber.dispose()
-  })
-})

packages/host/apiproxy/tests/api-proxy-fork.spec.ts

@@ -82,7 +82,7 @@ function liveAgent(
 }
 
 const api = (ctx: Context) => createApiProxy(ctx, {
-  defaultTarget: () => ({ provider: 'default-provider', model: 'default-model' }),
+  defaultModelSelection: () => ({ provider: 'default-provider', model: 'default-model' }),
   cwd: '/tmp',
   workspaceRoot: '/tmp',
 })
@@ -254,7 +254,7 @@ describe('sessions.fork', () => {
     await ctx.fiber.dispose()
   })
 
-  it('installs the latest logged model target before the child can run', async () => {
+  it('installs the latest logged model selection before the child can run', async () => {
     const ctx = await composed()
     const source = liveAgent(ctx, 'session-routed', 1)
     source.append('request/header', {

packages/host/apiproxy/tests/api-proxy-models.spec.ts

@@ -1,6 +1,6 @@
 /**
  * Web session model-directory and selection behavior: dynamic provider grouping,
- * provider-local catalog failures, logged-target restoration without stale
+ * provider-local catalog failures, logged-selection restoration without stale
  * catalog injection, advisory pass-through models, and the prompt-assembly
  * boundary for a running selection change.
  */
@@ -119,13 +119,13 @@ function expectValue<T>(response: { result: { ok: true; value: T } | { ok: false
 }
 
 describe('Web session model selection', () => {
-  it('groups successful providers and leaves an unlisted current target out of the catalog', async () => {
+  it('groups successful providers and leaves an unlisted current selection out of the catalog', async () => {
     const { ctx, sessionId } = await harness({
       provider: 'deepseek-official',
       model: 'private-preview',
       reasoningEffort: ReasoningEffortId('max'),
     })
-    const api = createApiProxy(ctx, { defaultTarget: () => ({ provider: 'deepseek-official', model: 'deepseek-chat' }), cwd: '/tmp', workspaceRoot: '/tmp' })
+    const api = createApiProxy(ctx, { defaultModelSelection: () => ({ provider: 'deepseek-official', model: 'deepseek-chat' }), cwd: '/tmp', workspaceRoot: '/tmp' })
 
     const catalog = expectValue(await api.sessions.models(request({ sessionId })))
     expect(catalog.current).toEqual({
@@ -160,7 +160,7 @@ describe('Web session model selection', () => {
 
   it('accepts an advisory-unlisted model, rejects an unavailable provider, and switches only after the next assembly', async () => {
     const { ctx, agent, sessionId } = await harness()
-    const api = createApiProxy(ctx, { defaultTarget: () => ({ provider: 'deepseek-official', model: 'deepseek-chat' }), cwd: '/tmp', workspaceRoot: '/tmp' })
+    const api = createApiProxy(ctx, { defaultModelSelection: () => ({ provider: 'deepseek-official', model: 'deepseek-chat' }), cwd: '/tmp', workspaceRoot: '/tmp' })
     const seed: LlmCallConfig = { provider: 'seed', model: 'seed', temperature: 0.2 }
     const signal = new AbortController().signal
 
@@ -226,11 +226,11 @@ describe('Web session model selection', () => {
     await ctx.fiber.dispose()
   })
 
-  it('reads the host default live for a session whose log names no route', async () => {
+  it('reads the Agent default live for a session whose log names no selection', async () => {
     const { ctx, sessionId } = await harness()
     let stored = { provider: 'deepseek-official', model: 'deepseek-chat' }
     const api = createApiProxy(ctx, {
-      defaultTarget: () => stored,
+      defaultModelSelection: () => stored,
       cwd: '/tmp',
       workspaceRoot: '/tmp',
     })
@@ -248,14 +248,14 @@ describe('Web session model selection', () => {
     await ctx.fiber.dispose()
   })
 
-  it('keeps a session that logged a route on it when the host default moves', async () => {
+  it('keeps a session on its logged selection when the Agent default differs', async () => {
     const { ctx, sessionId } = await harness({
       provider: 'deepseek-official',
       model: 'deepseek-chat',
     })
     let stored = { provider: 'deepseek-official', model: 'deepseek-chat' }
     const api = createApiProxy(ctx, {
-      defaultTarget: () => stored,
+      defaultModelSelection: () => stored,
       cwd: '/tmp',
       workspaceRoot: '/tmp',
     })
@@ -271,9 +271,9 @@ describe('Web session model selection', () => {
     const saved: unknown[] = []
     let reject = false
     const api = createApiProxy(ctx, {
-      defaultTarget: () => ({ provider: 'deepseek-official', model: 'deepseek-chat' }),
-      persistDefaultTarget: (target) => {
-        saved.push(target)
+      defaultModelSelection: () => ({ provider: 'deepseek-official', model: 'deepseek-chat' }),
+      saveDefaultModelSelection: (selection) => {
+        saved.push(selection)
         return reject ? Promise.reject(new Error('read-only document')) : Promise.resolve()
       },
       cwd: '/tmp',
@@ -306,7 +306,7 @@ describe('Web session model selection', () => {
   it('refuses a prompt no adapter can route, and reports it on the directory', async () => {
     const { ctx, sessionId } = await harness()
     const api = createApiProxy(ctx, {
-      defaultTarget: () => ({ provider: 'deleted-gateway', model: 'deleted-model' }),
+      defaultModelSelection: () => ({ provider: 'deleted-gateway', model: 'deleted-model' }),
       cwd: '/tmp',
       workspaceRoot: '/tmp',
     })
@@ -339,7 +339,7 @@ describe('Web session model selection', () => {
     const api = createApiProxy(ctx, {
       // What a Models-page removal leaves behind: the settings document still
       // names the route the user last picked, and nothing serves it.
-      defaultTarget: () => ({ provider: 'deleted-gateway', model: 'deleted-model' }),
+      defaultModelSelection: () => ({ provider: 'deleted-gateway', model: 'deleted-model' }),
       cwd: '/tmp',
       workspaceRoot: '/tmp',
     })

packages/host/apiproxy/tests/api-proxy-projections.spec.ts

@@ -68,7 +68,7 @@ function seedMessages(session: Session, count: number): void {
   }
 }
 
-const api = (ctx: Context) => createApiProxy(ctx, { defaultTarget: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
+const api = (ctx: Context) => createApiProxy(ctx, { defaultModelSelection: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
 
 describe('session.history projections block', () => {
   it('serves the unit value on the tail page with asOfSeq = last event seq', async () => {

packages/host/apiproxy/tests/api-proxy-question.spec.ts

@@ -14,7 +14,7 @@ async function harness(): Promise<{ ctx: Context; api: ApiProxy }> {
   await ctx.plugin(UserInteractionService)
   return {
     ctx,
-    api: createApiProxy(ctx, { defaultTarget: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' }),
+    api: createApiProxy(ctx, { defaultModelSelection: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' }),
   }
 }
 

packages/host/apiproxy/tests/api-proxy-rename.spec.ts

@@ -68,7 +68,7 @@ function liveAgent(ctx: Context, id: string, turns: number): Session {
   return session
 }
 
-const api = (ctx: Context) => createApiProxy(ctx, { defaultTarget: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
+const api = (ctx: Context) => createApiProxy(ctx, { defaultModelSelection: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
 
 describe('sessions.rename', () => {
   it('accepts through the composed title service: normalized user-source event, echoed seq', async () => {

packages/host/apiproxy/tests/api-proxy-search.spec.ts

@@ -27,7 +27,7 @@ vi.mock('node:fs/promises', async (importOriginal) => {
 })
 
 const sid = (value: string): SessionId => value as SessionId
-const defaults = { defaultTarget: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' }
+const defaults = { defaultModelSelection: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' }
 
 function request(query: string): RpcRequest<{ query: string }> {
   return { rpcId: RpcId(`search-${query}`), payload: { query } }
@@ -165,7 +165,7 @@ describe('session.search', () => {
     expect(searchSessions).not.toHaveBeenCalled()
   })
 
-  it('rejects snippets whose provider provenance violates the Host filters', async () => {
+  it('rejects snippets whose recorded provider violates the Host filters', async () => {
     const ctx = await baseContext()
     const visible = hit('visible')
     ctx.sessions.create(visible.header.id, { meta: visible.header })

packages/host/apiproxy/tests/api-proxy-subagents.spec.ts

@@ -19,6 +19,7 @@ function bench(options: {
   childStatus?: 'idle' | 'running'
   entries?: object[]
   followupError?: Error
+  interruptError?: Error
   listError?: Error
   /** Persistence forgets the child entirely (the vanished-mid-read race). */
   storedChild?: false
@@ -53,6 +54,12 @@ function bench(options: {
   ) => options.followupError === undefined
     ? Promise.resolve('message-1')
     : Promise.reject(options.followupError))
+  const interrupt = vi.fn((
+    _targetSessionId: SessionId,
+    _authority: { kind: 'user'; parentSessionId: SessionId },
+  ) => {
+    if (options.interruptError !== undefined) throw options.interruptError
+  })
   const childHeader = {
     version: 0, id: CHILD, createdAt: 1, cwd: '/proj', parentSession: options.historyParent ?? PARENT,
   } satisfies SessionHeader
@@ -72,7 +79,7 @@ function bench(options: {
   })
   const ctx = new Context()
   ctx.provide('agents', { get: getAgent })
-  ctx.provide('subagents', { listChildren, followup })
+  ctx.provide('subagents', { listChildren, followup, interrupt })
   ctx.provide('sessions', {
     get: (id: SessionId) => options.liveChild === true && id === CHILD
       ? { id: CHILD, header: childHeader, events: childEvents }
@@ -84,13 +91,13 @@ function bench(options: {
     locate: () => undefined,
   })
   // The gateway's own projection push feed subscribes at construction; the
-  // no-op disposer keeps that seam quiet while these tests pin history reads.
+  // no-op disposer keeps that feed quiet while these tests pin history reads.
   ctx.provide('sessionProjections', { snapshot, restore, onChanged: () => () => {} })
   ctx.provide('userInteraction', { registerProvider: () => () => {} })
   const api = createApiProxy(ctx, {
-    defaultTarget: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp',
+    defaultModelSelection: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp',
   })
-  return { api, getAgent, listChildren, inspect, snapshot, restore, followup, parent }
+  return { api, getAgent, listChildren, inspect, snapshot, restore, followup, interrupt, parent }
 }
 
 describe('subagent gateway', () => {
@@ -309,4 +316,48 @@ describe('subagent gateway', () => {
       error: { code: 'internal', message: 'subagent prompt failed' },
     })
   })
+
+  it('interrupts through the core primitive alone while the parent Agent is offline', async () => {
+    const { api, interrupt, getAgent, listChildren, inspect } = bench({ parentLive: false })
+    const response = await api.subagents.interrupt(request({
+      parentSessionId: PARENT, childSessionId: CHILD, mode: 'continuable' as const,
+    }))
+    expect(response.rpcId).toBe('subagent-rpc')
+    expect(response.result).toEqual({ ok: true, value: { accepted: true } })
+    expect(interrupt).toHaveBeenCalledExactlyOnceWith(CHILD, { kind: 'user', parentSessionId: PARENT })
+    // No parent-registry, catalog, or history dependency: this is what keeps a
+    // live child interruptible after its parent Agent went offline.
+    expect(getAgent).not.toHaveBeenCalled()
+    expect(listChildren).not.toHaveBeenCalled()
+    expect(inspect).not.toHaveBeenCalled()
+  })
+
+  it('maps interrupt authorization rejection without touching other services', async () => {
+    const { api, listChildren } = bench({
+      interruptError: new SubagentError('secret lineage', 'UNAUTHORIZED'),
+    })
+    const response = await api.subagents.interrupt(request({
+      parentSessionId: PARENT, childSessionId: CHILD, mode: 'continuable' as const,
+    }))
+    expect(response.result).toEqual({
+      ok: false,
+      error: {
+        code: 'subagent-unauthorized',
+        message: 'subagent does not belong to this parent',
+        details: { childSessionId: CHILD },
+      },
+    })
+    expect(listChildren).not.toHaveBeenCalled()
+  })
+
+  it('hides unexpected interrupt failures behind the internal code', async () => {
+    const { api } = bench({ interruptError: new Error('secret activation state') })
+    const response = await api.subagents.interrupt(request({
+      parentSessionId: PARENT, childSessionId: CHILD, mode: 'continuable' as const,
+    }))
+    expect(response.result).toEqual({
+      ok: false,
+      error: { code: 'internal', message: 'subagent interrupt failed', details: {} },
+    })
+  })
 })

packages/host/apiproxy/tests/api-proxy-view.spec.ts

@@ -105,7 +105,7 @@ async function collect(iterable: AsyncIterable<RpcRequest<MuxFrame>>, count: num
 describe('mux live view computation', () => {
   it('attaches the three standard card views, omits view without a presenter, soft-falls on throw', async () => {
     const { ctx } = await harness()
-    const api = createApiProxy(ctx, { defaultTarget: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
+    const api = createApiProxy(ctx, { defaultModelSelection: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
     const abort = new AbortController()
     const stream = api.events.mux({ rpcId: RpcId('t-mux'), payload: {} }, abort.signal)
     const collected = collect(stream, 9, abort)
@@ -170,7 +170,7 @@ describe('mux live view computation', () => {
 
   it('serves history entries with call/result views, backscan pairing, and soft-falls', async () => {
     const { ctx } = await harness()
-    const api = createApiProxy(ctx, { defaultTarget: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
+    const api = createApiProxy(ctx, { defaultModelSelection: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
     const session = ctx.sessions.create()
     // history resolves the agent first; a live structural stub is enough (only
     // .session is read on this path).
@@ -236,9 +236,9 @@ describe('mux live view computation', () => {
     expect('view' in (byKey.get('tool/result:h-plain') ?? {})).toBe(false)
   })
 
-  it('counts only append-origin messages toward maxMessages and keeps compaction provenance whole', async () => {
+  it('counts only append-origin messages toward maxMessages and keeps each compaction summary with its replacement', async () => {
     const { ctx } = await harness()
-    const api = createApiProxy(ctx, { defaultTarget: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
+    const api = createApiProxy(ctx, { defaultModelSelection: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
     const session = ctx.sessions.create()
     ctx.agents.register({ id: session.id, session, status: 'idle', ctx } as Agent)
     session.append('turn/start', { turn: 1 })
@@ -247,7 +247,7 @@ describe('mux live view computation', () => {
     const third = appendUserText(session, 'second prompt')
     appendAssistantText(session, 'second reply', 2)
     const shadowed = [...session.surface.nodes]
-    // A compaction transaction: log-only provenance immediately followed by the
+    // A compaction transaction: a log-only summary record immediately followed by the
     // replacement that shadows the range.
     const summary = appendExtension(session, 'compact/summary', {
       summary: [{ type: 'text', text: 'summary' }],
@@ -277,7 +277,7 @@ describe('mux live view computation', () => {
     expect(messages.map(event => event.seq)).toEqual([third.seq, third.seq + 1, third.seq + 3])
     expect(page.some(event => event.seq === first.seq)).toBe(false)
     expect(response.result.value.hasMore).toBe(true)
-    // The range stays contiguous, so the checkpoint's provenance is readable on
+    // The range stays contiguous, so the checkpoint's summary record is readable on
     // the same page as the checkpoint itself.
     const summaryIndex = page.findIndex(event => event.seq === summary.seq)
     expect(summaryIndex).toBeGreaterThan(-1)
@@ -287,7 +287,7 @@ describe('mux live view computation', () => {
 
   it('drops a disposed session from the live open-call table (result after dispose gets no view)', async () => {
     const { ctx } = await harness()
-    const api = createApiProxy(ctx, { defaultTarget: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
+    const api = createApiProxy(ctx, { defaultModelSelection: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
     const abort = new AbortController()
     const stream = api.events.mux({ rpcId: RpcId('t-mux3'), payload: {} }, abort.signal)
 
@@ -308,7 +308,7 @@ describe('mux live view computation', () => {
 
   it('pairs a result after turn/end via the in-memory backscan fallback', async () => {
     const { ctx } = await harness()
-    const api = createApiProxy(ctx, { defaultTarget: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
+    const api = createApiProxy(ctx, { defaultModelSelection: () => ({ provider: 'p', model: 'm' }), cwd: '/tmp', workspaceRoot: '/tmp' })
     const abort = new AbortController()
     const stream = api.events.mux({ rpcId: RpcId('t-mux2'), payload: {} }, abort.signal)
     const collected = collect(stream, 4, abort)

packages/host/apiproxy/tests/api-proxy-workspace.spec.ts

@@ -59,7 +59,7 @@ function stubAgent(session: Session): Agent {
 
 /** Compose the API over real Session, Agent, Storage, Domain, and Workspace services. */
 async function harness(
-  workspaceRoot = realpathSync(mkdtempSync(join(tmpdir(), 'dsh-apiproxy-workspace-'))),
+  workspaceRoot = realpathSync.native(mkdtempSync(join(tmpdir(), 'dsh-apiproxy-workspace-'))),
   picker: DirectoryPickerCapability = { kind: 'native', pick: async () => null },
   extras: { openPath?: (path: string, signal: AbortSignal) => Promise<void> } = {},
 ) {
@@ -100,7 +100,7 @@ async function harness(
   // object per harness mirrors the seam's stability contract.
   ctx.provide('directoryPicker', { capability: () => picker } as never)
   const api = createApiProxy(ctx, {
-    defaultTarget: () => ({ provider: 'test', model: 'test-model' }),
+    defaultModelSelection: () => ({ provider: 'test', model: 'test-model' }),
     cwd: workspaceRoot,
     workspaceRoot,
     ...extras.openPath === undefined ? {} : { openPath: extras.openPath },

packages/host/apiproxy/tests/client-handler.spec.ts

@@ -23,6 +23,7 @@ function scriptedApi(overrides: {
   host?: Partial<ApiProxy['host']>
   commands?: Partial<ApiProxy['commands']>
   skills?: Partial<ApiProxy['skills']>
+  agentPresets?: Partial<ApiProxy['agentPresets']>
   events?: Partial<ApiProxy['events']>
   goals?: Partial<ApiProxy['goals']>
   settings?: Partial<ApiProxy['settings']>
@@ -41,7 +42,7 @@ function scriptedApi(overrides: {
       history: r => ok(r, {
         events: [],
         hasMore: false,
-        modelTarget: { provider: 'deepseek-official', model: 'deepseek-v4-flash' },
+        modelSelection: { provider: 'deepseek-official', model: 'deepseek-v4-flash' },
       }),
       models: r => ok(r, {
         current: { provider: 'deepseek-official', model: 'deepseek-v4-flash' },
@@ -63,6 +64,7 @@ function scriptedApi(overrides: {
       list: r => ok(r, { entries: [], parentAvailable: false }),
       history: r => ok(r, { events: [], hasMore: false }),
       prompt: r => ok(r, { messageId: 'message-1' as never }),
+      interrupt: r => ok(r, { accepted: true as const }),
       ...overrides.subagents,
     },
     host: {
@@ -87,6 +89,15 @@ function scriptedApi(overrides: {
       ...overrides.commands,
     },
     skills: { list: r => ok(r, { skills: [] }), ...overrides.skills },
+    agentPresets: {
+      list: r => ok(r, { presets: [], authorable: false, hasDocument: false }),
+      select: r => ok(r, { agentPreset: r.payload.agentPreset }),
+      read: r => ok(r, { agentPreset: r.payload.agentPreset, trust: 'user' as const, content: '' }),
+      copy: r => ok(r, { agentPreset: r.payload.agentPreset }),
+      openDocument: r => ok(r, { opened: true as const }),
+      remove: r => ok(r, {}),
+      ...overrides.agentPresets,
+    },
     goals: {
       create: err,
       edit: err,
@@ -221,6 +232,18 @@ describe('unary round trip', () => {
     expect(appended.result.ok).toBe(true)
   })
 
+  it('routes the agent-preset roster and switch through the wire', async () => {
+    const c = client(scriptedApi())
+
+    const listed = await c.agentPresets.list({})
+    expect(listed.result).toEqual({ ok: true, value: { presets: [], authorable: false, hasDocument: false } })
+
+    // The switch carries the session it is about: the host refuses one whose
+    // conversation has started, and it can only know which by id.
+    const selected = await c.agentPresets.select({ sessionId: sid('s1'), agentPreset: 'standard' })
+    expect(selected.result).toEqual({ ok: true, value: { agentPreset: 'standard' } })
+  })
+
   it('passes business errors through as 200 + err result, not a throw', async () => {
     const api = scriptedApi({
       sessions: {
@@ -248,6 +271,32 @@ describe('unary round trip', () => {
     }
   })
 
+  it('round-trips subagent.interrupt and rejects a one-shot or incomplete address', async () => {
+    const interrupt = vi.fn((r: RpcRequest<unknown>) => ok(r, { accepted: true as const }))
+    const api = scriptedApi({ subagents: { interrupt } })
+    const c = client(api)
+
+    const accepted = await c.subagents.interrupt({
+      parentSessionId: sid('parent'), childSessionId: sid('child'), mode: 'continuable',
+    })
+    expect(accepted.result).toEqual({ ok: true, value: { accepted: true } })
+    expect(interrupt).toHaveBeenCalledTimes(1)
+
+    // The wire schema owns the mode fence: a one-shot address never reaches the impl.
+    const oneShot = await c.subagents.interrupt({
+      parentSessionId: sid('parent'), childSessionId: sid('child'), mode: 'one-shot',
+    } as never)
+    expect(oneShot.result.ok).toBe(false)
+    if (!oneShot.result.ok) expect(oneShot.result.error.code).toBe('bad-request')
+
+    const incomplete = await c.subagents.interrupt({
+      parentSessionId: sid('parent'), mode: 'continuable',
+    } as never)
+    expect(incomplete.result.ok).toBe(false)
+    if (!incomplete.result.ok) expect(incomplete.result.error.code).toBe('bad-request')
+    expect(interrupt).toHaveBeenCalledTimes(1)
+  })
+
   it('rejects a method/path mismatch as bad-request', async () => {
     const handler = toFetchHandler(scriptedApi())
     const body = { type: 'client-request', rpcId: 'r1', method: 'session.create', payload: {} }

packages/host/apiproxy/tests/fetch-carrier.spec.ts

@@ -128,6 +128,9 @@ function fakeApi(overrides: Partial<{ muxFrames: MuxFrame[]; hostFrames: HostFra
           result: { ok: true, value: { messageId: 'message-1' as never } },
         }
       },
+      async interrupt(request) {
+        return { rpcId: request.rpcId, result: { ok: true, value: { accepted: true as const } } }
+      },
     },
     host: {
       async describe(request) {
@@ -194,6 +197,32 @@ function fakeApi(overrides: Partial<{ muxFrames: MuxFrame[]; hostFrames: HostFra
         return { rpcId: request.rpcId, result: { ok: true, value: { matched: false } } }
       },
     },
+    agentPresets: {
+      list(request: RpcRequest<{}>) {
+        return Promise.resolve({
+          rpcId: request.rpcId,
+          result: { ok: true as const, value: { presets: [], authorable: false, hasDocument: false } },
+        })
+      },
+      select(request: RpcRequest<{ agentPreset: string }>) {
+        const value = { agentPreset: request.payload.agentPreset }
+        return Promise.resolve({ rpcId: request.rpcId, result: { ok: true as const, value } })
+      },
+      read(request: RpcRequest<{ agentPreset: string }>) {
+        const value = { agentPreset: request.payload.agentPreset, trust: 'user' as const, content: '' }
+        return Promise.resolve({ rpcId: request.rpcId, result: { ok: true as const, value } })
+      },
+      copy(request: RpcRequest<{ from: string; agentPreset: string }>) {
+        const value = { agentPreset: request.payload.agentPreset }
+        return Promise.resolve({ rpcId: request.rpcId, result: { ok: true as const, value } })
+      },
+      openDocument(request: RpcRequest<{ agentPreset: string }>) {
+        return Promise.resolve({ rpcId: request.rpcId, result: { ok: true as const, value: { opened: true as const } } })
+      },
+      remove(request: RpcRequest<{ agentPreset: string }>) {
+        return Promise.resolve({ rpcId: request.rpcId, result: { ok: true as const, value: {} } })
+      },
+    },
     skills: {
       async list(request) {
         return { rpcId: request.rpcId, result: { ok: true, value: { skills: [{ name: 'commit-helper', description: 'Git commits', modelInvocable: true }] } } }
@@ -337,6 +366,28 @@ describe('unary round trip (handler ⇄ client, no network)', () => {
     expect((await c.host.describe({})).result.ok).toBe(true)
   })
 
+  it('round-trips every agent-preset method, authoring included', async () => {
+    const c = client()
+
+    // The whole domain crosses the carrier: the roster a picker reads, the
+    // per-session switch, and the authoring calls the settings page makes.
+    // Each has its own request schema, so a registration missing from either
+    // half fails here rather than in the browser.
+    expect((await c.agentPresets.list({})).result).toEqual({
+      ok: true, value: { presets: [], authorable: false, hasDocument: false },
+    })
+    expect((await c.agentPresets.select({ sessionId: 's' as never, agentPreset: 'minimal' })).result)
+      .toEqual({ ok: true, value: { agentPreset: 'minimal' } })
+    expect((await c.agentPresets.read({ agentPreset: 'mine' })).result).toEqual({
+      ok: true, value: { agentPreset: 'mine', trust: 'user', content: '' },
+    })
+    expect((await c.agentPresets.copy({ from: 'standard', agentPreset: 'mine' })).result)
+      .toEqual({ ok: true, value: { agentPreset: 'mine' } })
+    expect((await c.agentPresets.openDocument({ agentPreset: 'mine' })).result)
+      .toEqual({ ok: true, value: { opened: true } })
+    expect((await c.agentPresets.remove({ agentPreset: 'mine' })).result).toEqual({ ok: true, value: {} })
+  })
+
   it('round-trips the native picker without the default unary timeout', async () => {
     const api = fakeApi()
     api.host.pickDirectory = async (request) => {
@@ -433,6 +484,11 @@ describe('unary round trip (handler ⇄ client, no network)', () => {
       mode: 'continuable',
       content: [],
     })).result).toEqual({ ok: true, value: { messageId: 'message-1' } })
+    expect((await c.subagents.interrupt({
+      parentSessionId: 'parent' as never,
+      childSessionId: 'child' as never,
+      mode: 'continuable',
+    })).result).toEqual({ ok: true, value: { accepted: true } })
   })
 
   it('keeps caller and connection aborts on command.execute', async () => {

packages/host/apiproxy/tests/native-path-opener.spec.ts

@@ -16,7 +16,7 @@ vi.mock('node:child_process', () => ({ execFile: execFileMock }))
 
 import { release as osRelease } from 'node:os'
 import { describe, expect, it, vi } from 'vitest'
-import { openNativePath, openNativeTextFile, type PathOpenerRunner } from '../src/native-path-opener.ts'
+import { canOpenNativePath, openNativePath, openNativeTextFile, type PathOpenerRunner } from '../src/native-path-opener.ts'
 
 const signal = () => new AbortController().signal
 
@@ -287,3 +287,35 @@ describe('browser-renderable documents', () => {
     ])
   })
 })
+
+describe('canOpenNativePath', () => {
+  it('always answers yes where the desktop is part of the platform', () => {
+    expect(canOpenNativePath({ platform: 'darwin', env: {} })).toBe(true)
+    expect(canOpenNativePath({ platform: 'win32', env: {} })).toBe(true)
+  })
+
+  it('requires a display server or WSL interop on linux', () => {
+    const linux = { platform: 'linux' as const, osRelease: '6.8.0-generic' }
+    // Headless is the case the capability exists for: `xdg-open` would spawn
+    // into nothing, so a surface should show the path as text instead.
+    expect(canOpenNativePath({ ...linux, env: {} })).toBe(false)
+    expect(canOpenNativePath({ ...linux, env: { DISPLAY: ':0' } })).toBe(true)
+    expect(canOpenNativePath({ ...linux, env: { WAYLAND_DISPLAY: 'wayland-0' } })).toBe(true)
+    expect(canOpenNativePath({
+      platform: 'linux', osRelease: '5.15.153.1-microsoft-standard-WSL2', env: {},
+    })).toBe(true)
+  })
+
+  it('answers no on a platform the opener does not support', () => {
+    expect(canOpenNativePath({ platform: 'freebsd', env: {} })).toBe(false)
+  })
+
+  it('samples the ambient environment when no override is supplied', () => {
+    const env = process.env
+    const marked = (value: string | undefined): boolean => value !== undefined && value !== ''
+    const expected = marked(env.WSL_DISTRO_NAME) || marked(env.WSL_INTEROP)
+      || marked(env.DISPLAY) || marked(env.WAYLAND_DISPLAY)
+
+    expect(canOpenNativePath({ platform: 'linux', osRelease: '6.8.0-generic' })).toBe(expected)
+  })
+})

packages/host/apiproxy/tests/rpc-schemas.spec.ts

@@ -32,6 +32,9 @@ import {
   commandListRequestSchema, commandListValueSchema,
 } from '../src/api/commands.schema.ts'
 import { skillEntrySchema, skillListRequestSchema, skillListValueSchema } from '../src/api/skills.schema.ts'
+import {
+  agentPresetEntrySchema, agentPresetListValueSchema, agentPresetOpenDocumentValueSchema,
+} from '../src/api/agent-presets.schema.ts'
 import { hostFrameSchema, muxFrameSchema, askUserQuestionItemSchema } from '../src/api/events.schema.ts'
 import { approvalRequestIdSchema, approvalResponsePayloadSchema } from '../src/api/approvals.schema.ts'
 import { askUserQuestionAnswerSchema, questionResponsePayloadSchema } from '../src/api/questions.schema.ts'
@@ -192,7 +195,7 @@ describe('sessions domain schemas', () => {
     expect(sessionHistoryValueSchema.parse({
       events: [],
       hasMore: false,
-      modelTarget: { provider: 'deepseek-official', model: 'deepseek-v4-flash' },
+      modelSelection: { provider: 'deepseek-official', model: 'deepseek-v4-flash' },
     }).hasMore).toBe(false)
     expect(sessionModelsRequestSchema.parse({ sessionId: 's1' }).sessionId).toBe('s1')
     expect(sessionModelsValueSchema.parse({
@@ -508,3 +511,27 @@ describe('respond payload schemas', () => {
     expect(payload.sessionId).toBe('s')
   })
 })
+
+describe('agent-preset schemas', () => {
+  it('accepts a roster row and rejects an unknown trust', () => {
+    expect(agentPresetEntrySchema.parse({ id: 'standard', trust: 'system', isDefault: true }))
+      .toEqual({ id: 'standard', trust: 'system', isDefault: true })
+    expect(() => agentPresetEntrySchema.parse({ id: 'x', trust: 'root', isDefault: false })).toThrow()
+    expect(() => agentPresetEntrySchema.parse({ id: '', trust: 'user', isDefault: false })).toThrow()
+  })
+
+  it('accepts an empty roster', () => {
+    // A deployment composing no presets still reports its authoring and
+    // native-open capabilities, so a surface knows what to offer.
+    expect(agentPresetListValueSchema.parse({ presets: [], authorable: false, hasDocument: false }))
+      .toEqual({ presets: [], authorable: false, hasDocument: false })
+  })
+
+  it('answers the open-document union by its discriminant', () => {
+    expect(agentPresetOpenDocumentValueSchema.parse({ opened: true })).toEqual({ opened: true })
+    expect(agentPresetOpenDocumentValueSchema.parse({ opened: false, path: '/presets/mine' }))
+      .toEqual({ opened: false, path: '/presets/mine' })
+    // A closed reply must carry the path the surface shows instead.
+    expect(() => agentPresetOpenDocumentValueSchema.parse({ opened: false })).toThrow()
+  })
+})