refactor(gui): features register their own settings surfaces

Settings collaboration direction (recorded in the note): the shell only
provides composition faces — feature plugins register themselves. The
General section moves into the ui-settings shell (order 0, skeleton
rows) and declares the settings.general.item list slot; locale registers
the Language row and ui-theme the Appearance row (each with its own
store mirror, dictionaries, and ledger-judged deferral); the
ui-settings-general package is gone. ui-settings-models becomes
ui-models — a feature package that contributes its Settings section
rather than a settings-owned satellite. The item-slot SlotMap entry is
authored in the ui-settings contract and repeated verbatim in
locale/ui-theme (reference-cycle avoidance; declaration merging keeps
the copies identical).

packages/client/ui-models/README.md

@@ -0,0 +1,15 @@
+# @deepseek-ai/dsh-client-ui-models
+
+Models settings section plugin: registers the `models` nav entry into `settings.section` with an intentionally empty content column — model management lands in a later phase.
+
+## Model Experience
+
+None, as the section renders an empty browser UI column; nothing here reaches a model request.
+
+#### KV Cache effect
+
+None; this package neither assembles nor sends a provider request.
+
+## Known Limitations and Deferred Work
+
+- **Content column is empty by design** — provider list, editing form, and activation flow are deferred until the model-management service exists.

packages/client/ui-models/package.json

@@ -0,0 +1,63 @@
+{
+  "name": "@deepseek-ai/dsh-client-ui-models",
+  "description": "Models feature plugin: registers its Settings section (nav entry, empty content column; model management lands later)",
+  "version": "0.0.1",
+  "private": true,
+  "type": "module",
+  "main": "lib/index.js",
+  "types": "lib/types/index.d.ts",
+  "exports": {
+    ".": {
+      "types": "./lib/types/index.d.ts",
+      "default": "./lib/index.js"
+    },
+    "./invariant": {
+      "types": "./lib/types/invariant.d.ts",
+      "default": "./lib/invariant.js"
+    },
+    "./client": {
+      "types": "./lib/types/client/index.d.ts",
+      "default": "./lib/client.js"
+    },
+    "./src/*": "./src/*",
+    "./package.json": "./package.json"
+  },
+  "dshClient": {
+    "inject": [
+      "@deepseek-ai/dsh-client-runtime",
+      "@deepseek-ai/dsh-client-ui-settings",
+      "@deepseek-ai/dsh-client-locale"
+    ],
+    "platform": "web"
+  },
+  "scripts": {
+    "bundle": "tsdown",
+    "watch": "tsdown --watch"
+  },
+  "license": "BSD-3-Clause",
+  "peerDependencies": {
+    "@deepseek-ai/dsh-client-runtime": "^0.0.1",
+    "@deepseek-ai/dsh-client-ui-slots": "^0.0.1",
+    "@deepseek-ai/dsh-invariants": "^0.0.1",
+    "cordis": "^4.0.0-rc.7",
+    "react": "^18.2.0"
+  },
+  "devDependencies": {
+    "@deepseek-ai/dsh-client-locale": "workspace:^",
+    "@deepseek-ai/dsh-client-runtime": "workspace:^",
+    "@deepseek-ai/dsh-client-ui-settings": "workspace:^",
+    "@deepseek-ai/dsh-client-ui-slots": "workspace:^",
+    "@deepseek-ai/dsh-invariants": "workspace:^",
+    "@types/react": "~18.3.1",
+    "cordis": "^4.0.0-rc.7",
+    "react": "^18.2.0"
+  },
+  "files": [
+    "lib/index.js",
+    "lib/invariant.js",
+    "lib/client.js",
+    "lib/types/**/*.d.ts",
+    "lib/types/**/*.d.ts.map",
+    "src"
+  ]
+}

packages/client/ui-models/src/client/ModelsSection.tsx

@@ -0,0 +1,13 @@
+/**
+ * Models settings section: an intentionally empty content column — the nav
+ * entry exists so the section slot composition is visible; model management
+ * lands in a later phase.
+ */
+
+/**
+ * Render the (empty) Models section content column.
+ * @returns null — no content this phase.
+ */
+export function ModelsSection() {
+  return null
+}

packages/client/ui-models/src/client/index.ts

@@ -0,0 +1,67 @@
+/**
+ * Models settings section plugin, browser half. Registers the `models` nav
+ * entry into the shell-declared `settings.section` list slot; the content
+ * column is intentionally empty until model management lands. Export
+ * discipline: packages/client/AGENTS.md.
+ */
+import type { ClientContext } from '@deepseek-ai/dsh-client-runtime/client'
+// Type-only: pulls the shell's SlotMap merge (the 'settings.section' entry).
+import type {} from '@deepseek-ai/dsh-client-ui-settings/client'
+// Type-only: pulls the locale plugin's Context merge (ctx.locale).
+import type {} from '@deepseek-ai/dsh-client-locale/client'
+import { ModelsSection } from './ModelsSection.tsx'
+
+/**
+ * Required services (cordis fiber inject). The target slot is declared by
+ * ui-settings' apply, whose activation order relative to this one is NOT
+ * constrained; registration goes through declaration-aware deferral.
+ */
+export const inject = ['slots', 'locale']
+
+/**
+ * Register the Models section once the `settings.section` declaration is on
+ * the ledger.
+ * @param ctx - client root context.
+ */
+export function apply(ctx: ClientContext): void {
+  ctx.effect(() => {
+    const disposers = [
+      ctx.locale.register('settings.models', 'zh', { nav: '模型' }),
+      ctx.locale.register('settings.models', 'en', { nav: 'Models' }),
+    ]
+    return () => { for (const dispose of disposers) dispose() }
+  }, 'ui-models: nav copy dictionaries')
+  // Declaration-aware registration; the LEDGER is the has-registered judge
+  // (not a local flag): after an HMR collapse re-declares the slot, the
+  // cascade already removed our entry, and a stale disposer must not block
+  // the re-registration.
+  ctx.effect(() => {
+    let dispose: (() => void) | undefined
+    const tryRegister = (): void => {
+      if (ctx.slots.spec('settings.section') === undefined) return
+      if (ctx.slots.entries('settings.section').some(e => e.component === ModelsSection)) return
+      dispose = ctx.slots.register({
+        name: 'settings.section',
+        id: 'models',
+        order: 10,
+        label: ctx.locale.bind('settings.models')('nav'),
+      }, ModelsSection)
+    }
+    // Nav labels are registrant-localized: re-register on locale change so
+    // the ledger carries fresh text (the version bump re-renders the shell).
+    // Dispose-then-requery: after an HMR collapse the disposer is stale and
+    // the ledger/spec re-check keeps this path an idempotent no-op.
+    const offLocale = ctx.on('locale/change', () => {
+      dispose?.()
+      dispose = undefined
+      tryRegister()
+    })
+    const unsubscribe = ctx.slots.subscribe('settings.section', () => { tryRegister() })
+    tryRegister()
+    return () => {
+      offLocale()
+      unsubscribe()
+      dispose?.()
+    }
+  }, 'ui-models: settings section registration')
+}

packages/client/ui-models/src/css-modules.d.ts

@@ -0,0 +1,6 @@
+declare module '*.module.css' {
+  const classes: Record<string, string>
+  export default classes
+}
+
+declare module '*.css'

packages/client/ui-models/src/index.ts

@@ -0,0 +1,4 @@
+/** Host loader entry for the browser implementation exported from `./client`. */
+
+/** Host plugin body — no host-side behavior for the models settings plugin. */
+export function apply(): void {}

packages/client/ui-models/src/invariant.ts

@@ -0,0 +1,31 @@
+/**
+ * Package-owned invariant companion for `@deepseek-ai/dsh-client-ui-models`.
+ * @module @deepseek-ai/dsh-client-ui-models/invariant
+ */
+
+/* jscpd:ignore-start */
+import type { Context } from 'cordis'
+import type { InvariantInstaller } from '@deepseek-ai/dsh-invariants'
+
+const PACKAGE_NAME = '@deepseek-ai/dsh-client-ui-models'
+
+/** Cordis companion plugin name. */
+export const name = 'client-ui-models-invariant'
+/** Service required before the companion can reserve package ownership. */
+export const inject = ['invariants']
+
+/**
+ * No runtime invariant: a nav-entry-only section plugin rendering a fixed
+ * empty content column — it emits no cordis events and owns no cross-plugin
+ * mutable relation.
+ */
+const install: InvariantInstaller = () => {}
+
+/**
+ * Register this package's invariant companion.
+ * @param ctx - Cordis context carrying the invariant service.
+ * @returns the installed registration's disposer after setup succeeds.
+ */
+export const apply = (ctx: Context): Promise<() => void> =>
+  Promise.resolve(ctx.invariants.register(PACKAGE_NAME, install))
+/* jscpd:ignore-end */

packages/client/ui-models/tests/apply.spec.ts

@@ -0,0 +1,95 @@
+/** Models section registration: declaration-aware deferral, locale re-registration, and HMR recovery. */
+import { Context } from 'cordis'
+import { describe, expect, it } from 'vitest'
+import { SlotsService } from '@deepseek-ai/dsh-client-runtime/client'
+import { LocaleService } from '@deepseek-ai/dsh-client-locale/client'
+import { apply, inject } from '@deepseek-ai/dsh-client-ui-models/client'
+import { ModelsSection } from '../src/client/ModelsSection.tsx'
+
+async function bench() {
+  const ctx = new Context()
+  await ctx.plugin(SlotsService).await()
+  const locale = new LocaleService(ctx)
+  ctx.provide('locale', locale)
+  return { ctx, slots: ctx.get('slots') as SlotsService, locale }
+}
+
+function declare(slots: SlotsService): () => void {
+  return slots.register(
+    { name: 'root', children: { 'settings.section': { kind: 'list', scope: 'root' } } } as never,
+    () => null,
+  )
+}
+
+describe('ui-models apply', () => {
+  it('declares the services it uses', () => {
+    expect(inject).toEqual(['slots', 'locale'])
+  })
+
+  it('registers the models nav entry for declarations before or after apply', async () => {
+    const before = await bench()
+    declare(before.slots)
+    await before.ctx.plugin({ inject: [...inject], apply }).await()
+    const entry = before.slots.entries('settings.section')[0]!
+    expect(entry.component).toBe(ModelsSection)
+    expect(entry.options).toEqual({ id: 'models', order: 10, label: '模型' })
+
+    const after = await bench()
+    await after.ctx.plugin({ inject: [...inject], apply }).await()
+    expect(after.slots.entries('settings.section')).toHaveLength(0)
+    declare(after.slots)
+    await Promise.resolve()
+    expect(after.slots.entries('settings.section')[0]!.component).toBe(ModelsSection)
+    // The self-inflicted ledger notifications hit the duplicate guard.
+    expect(after.slots.entries('settings.section')).toHaveLength(1)
+  })
+
+  it('re-registers with fresh label text on locale change', async () => {
+    const b = await bench()
+    declare(b.slots)
+    await b.ctx.plugin({ inject: [...inject], apply }).await()
+    b.locale.setLocale('en')
+    expect(b.slots.entries('settings.section')[0]!.options.label).toBe('Models')
+    b.locale.setLocale('zh')
+    expect(b.slots.entries('settings.section')[0]!.options.label).toBe('模型')
+  })
+
+  it('locale change while the slot is undeclared stays a no-op', async () => {
+    const b = await bench()
+    await b.ctx.plugin({ inject: [...inject], apply }).await()
+    b.locale.setLocale('en')
+    expect(b.slots.entries('settings.section')).toHaveLength(0)
+    b.locale.setLocale('zh')
+  })
+
+  it('re-registers after an HMR collapse re-declares the slot (stale disposer must not block)', async () => {
+    const b = await bench()
+    const redeclare = declare(b.slots)
+    await b.ctx.plugin({ inject: [...inject], apply }).await()
+    expect(b.slots.entries('settings.section')).toHaveLength(1)
+    // Declarer unload: the cascade removes our entry while our local
+    // disposer variable goes stale.
+    redeclare()
+    expect(b.slots.entries('settings.section')).toHaveLength(0)
+    declare(b.slots)
+    await Promise.resolve()
+    expect(b.slots.entries('settings.section')[0]!.component).toBe(ModelsSection)
+    // The locale path also recovers through the same ledger re-check.
+    b.locale.setLocale('en')
+    expect(b.slots.entries('settings.section')[0]!.options.label).toBe('Models')
+    b.locale.setLocale('zh')
+  })
+
+  it('registers the zh/en nav dictionaries and disposes everything with the fiber', async () => {
+    const b = await bench()
+    declare(b.slots)
+    const fiber = b.ctx.plugin({ inject: [...inject], apply })
+    await fiber.await()
+    expect(b.locale.bind('settings.models')('nav')).toBe('模型')
+    await fiber.dispose()
+    expect(b.slots.entries('settings.section')).toHaveLength(0)
+    // The (ns, locale) seats are free again — the dictionary disposers ran.
+    expect(() => b.locale.register('settings.models', 'zh', {})).not.toThrow()
+    expect(() => b.locale.register('settings.models', 'en', {})).not.toThrow()
+  })
+})

packages/client/ui-models/tests/invariant.spec.ts

@@ -0,0 +1,23 @@
+import { describe, expect, it } from 'vitest'
+import { Context } from 'cordis'
+import * as ModelsInvariant from '@deepseek-ai/dsh-client-ui-models/invariant'
+import InvariantService from '@deepseek-ai/dsh-invariants'
+import { ModelsSection } from '../src/client/ModelsSection.tsx'
+
+describe('invariant companion', () => {
+  it('registers under the package name with an empty installer', async () => {
+    const ctx = new Context()
+    await ctx.plugin(InvariantService, { enabled: true })
+    await expect(ctx.plugin(ModelsInvariant).await()).resolves.toBeDefined()
+  })
+
+  it('node-half apply is a no-op host placeholder', async () => {
+    const { apply } = await import('@deepseek-ai/dsh-client-ui-models')
+    apply()
+    expect(true).toBe(true) // reaching here without throw is the contract
+  })
+
+  it('the section content column is intentionally empty this phase', () => {
+    expect(ModelsSection()).toBeNull()
+  })
+})

packages/client/ui-models/tsconfig.json

@@ -0,0 +1,30 @@
+{
+  "extends": "../../../tsconfig.base.client.json",
+  "compilerOptions": {
+    "rootDir": "src",
+    "outDir": "lib/types"
+  },
+  "include": [
+    "src"
+  ],
+  "references": [
+    {
+      "path": "../../../vendor/cordis"
+    },
+    {
+      "path": "../ui-slots"
+    },
+    {
+      "path": "../runtime"
+    },
+    {
+      "path": "../ui-settings"
+    },
+    {
+      "path": "../locale"
+    },
+    {
+      "path": "../../support/invariants"
+    }
+  ]
+}

packages/client/ui-models/tsdown.config.ts

@@ -0,0 +1,3 @@
+import { clientBundle } from '../tsdown.client.ts'
+
+export default clientBundle('@deepseek-ai/dsh-client-ui-models', ['lib/types/index.js', 'lib/types/invariant.js'])