fix(web-app,agent-presets): keep the goal service on the host plane

The Gateway serves the goal domain as Remote endpoints, and a Remote method
picks its receiver Service from a generated descriptor — `clear(agent, ref)`
takes its agent as a PARAMETER, so the invocation is direct and the receiver
resolves on the host. Behind the preset's entry-local realm there was nothing
to resolve, and every browser goal call answered `service-unavailable`: the
composer's Clear goal button left the bar on screen.

That is the `bash-env` criterion read from the other side. Injection is not the
only host relationship a Service can have; being READ from a host row is one
too. The registry is keyed by session, so one host instance serves every
session exactly as it did before presets. The preset keeps the model-facing
tool, which is the choice a preset is for.

Also reverts the cold-transcript presenter resolve: resuming an agent to reach
its presenters made the context meter drop its cache and token counts on every
cold-opened session, trading one silent degradation for another. The card
degradation it addressed is diagnosed and still open.

packages/bundle/web-app/cordis.patch.yml

@@ -237,14 +237,14 @@
 - id: tool-skill
   disabled: true
 
-- id: goal
-  disabled: true
-
-- id: goal-session
-  disabled: true
-
-- id: command-goal
-  disabled: true
+# The goal SERVICE, its session driver, and the `/goal` command STAY on the
+# host plane; only the model-facing tool moves. The Gateway serves the goal
+# domain as Remote endpoints, and a Remote method picks its receiver Service
+# from a generated descriptor — it resolves `goals` on the host, so a
+# per-session realm would answer `service-unavailable` for every browser call.
+# That is the `bash-env` criterion read from the other side: injection is not
+# the only host relationship a Service can have. The registry is keyed by
+# session, so one host instance serves every session exactly as before presets.
 
 - id: tool-goal
   disabled: true

packages/host/apiproxy/src/api-proxy.ts

@@ -1127,30 +1127,6 @@ export function createApiProxy(ctx: Context, defaults: ApiProxyDefaults): ApiPro
     return undefined
   }
 
-  /**
-   * The agent whose layer holds this session's tool presenters.
-   *
-   * A preset registers its tools into the agent's OWN layer, so a transcript
-   * read while no agent exists finds no presenter at all and every card
-   * degrades to the generic renderer — silently, because a viewless entry is
-   * also what a tool with no presenter produces. Reading therefore resolves
-   * the agent, through the same deduplicated resume every other session method
-   * takes, whenever a roster is composed.
-   *
-   * A deployment composing no roster keeps the storage-only read it always
-   * had: its tools are in the host layer, which needs no agent to address. A
-   * resolution failure is not a read failure either — the transcript still
-   * serves, with the generic cards it would have rendered anyway.
-   * @param sessionId - the transcript being read.
-   * @returns the agent to resolve presenters against, or undefined for none.
-   */
-  async function presenterAgentFor(sessionId: SessionId): Promise<Agent | undefined> {
-    const live = ctx.get('agents')?.get(sessionId)
-    if (live !== undefined || ctx.get('agentPresets') === undefined) return live
-    const found = await agentFor(sessionId)
-    return 'error' in found ? undefined : found.agent
-  }
-
   /** Read one transcript cut and optional projection baseline without acquiring an Agent owner. */
   async function historyStateFor(
     sessionId: SessionId,
@@ -1780,7 +1756,11 @@ export function createApiProxy(ctx: Context, defaults: ApiProxyDefaults): ApiPro
             details: {},
           })
         }
-        const page = historyPage(ctx, state.events, beforeSeq, maxMessages, await presenterAgentFor(sessionId))
+        // `ctx.get`, not `ctx.agents`: this is the COLD path, and a caller may
+        // serve history from storage with no agent registry composed at all.
+        // An absent registry means no live agent, which is the same answer a
+        // present one gives here — presenters fall back to the global layer.
+        const page = historyPage(ctx, state.events, beforeSeq, maxMessages, ctx.get('agents')?.get(sessionId))
         return ok(request, {
           events: page.events,
           hasMore: page.hasMore,

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

@@ -239,37 +239,3 @@ describe('a capability the session\'s preset mounts', () => {
     expect(failure.error.message).toContain('neither this session')
   })
 })
-
-describe('session.history presenters', () => {
-  it('resolves the live agent so a preset-composed presenter is reachable', async () => {
-    const { api, ctx } = await harness(['standard'])
-    await api.sessions.create(request({ sessionId: SessionId('h1'), agentPreset: 'standard' }))
-
-    const response = await api.sessions.history(request({ sessionId: SessionId('h1') }))
-
-    expect(response.result.ok).toBe(true)
-    expect(ctx.agents.get(SessionId('h1'))).toBeDefined()
-  })
-
-  it('serves the transcript when no agent can be resolved for it', async () => {
-    // The roster is composed, so the read tries; this harness resumes nothing.
-    // A resolution failure is not a read failure — the transcript still
-    // serves, with the generic cards a viewless entry renders.
-    const { api } = await harness(['standard'])
-
-    const response = await api.sessions.history(request({ sessionId: SessionId('h2') }))
-
-    expect(response.result.ok).toBe(false)
-    const failure = response.result as { ok: false; error: { code: string } }
-    expect(failure.error.code).toBe('session-not-found')
-  })
-
-  it('keeps the storage-only read when the deployment composes no roster', async () => {
-    const { api } = await harness()
-    await api.sessions.create(request({ sessionId: SessionId('h3') }))
-
-    const response = await api.sessions.history(request({ sessionId: SessionId('h3') }))
-
-    expect(response.result.ok).toBe(true)
-  })
-})