Merge remote-tracking branch 'refs/remotes/origin/worktree/web-multimodal-image-input' into worktree/pr555-simplify

# Conflicts:
#	.agents/notes/implemented/feature/2026-07-22-web-multimodal-image-input-and-durable-attachments.i18n.yaml
#	.agents/notes/implemented/feature/2026-07-22-web-multimodal-image-input-and-durable-attachments.md
#	.agents/notes/implemented/feature/2026-07-22-web-multimodal-image-input-and-durable-attachments.zh.md
#	apps/cli/README.i18n.yaml
#	apps/cli/README.md
#	apps/cli/README.zh.md
#	apps/cli/src/app-cli-entry.ts
#	packages/client/connection/src/client/fixture.ts
#	packages/client/ui-conversation/src/client/service.ts
#	packages/host/apiproxy/src/api-proxy.ts
#	packages/host/apiproxy/src/api/host.schema.ts
#	packages/host/apiproxy/src/api/host.ts
#	packages/host/apiproxy/tests/fetch-carrier.spec.ts

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

@@ -7,12 +7,6 @@ import { RpcId } from '../src/api/rpc.ts'
 import { toFetchHandler } from '../src/fetch/handler.ts'
 import { AbstractApiClient, InProcessApiClient } from '../src/fetch/client.ts'
 
-declare module '@deepseek-ai/dsh-llm' {
-  interface ModelModalityMap {
-    audio: 'audio'
-  }
-}
-
 /** Minimal in-memory ApiProxy: echoes rpcIds, scripts one frame per stream. */
 function fakeApi(overrides: Partial<{
   muxFrames: MuxFrame[]
@@ -259,26 +253,6 @@ describe('unary round trip (handler ⇄ client, no network)', () => {
     expect((await c.host.describe({})).result.ok).toBe(true)
   })
 
-  it('round-trips a declaration-merged model modality through host.describe', async () => {
-    const c = client(fakeApi({
-      hostDescription: {
-        version: 'v',
-        cwd: '/w',
-        attachedSessions: 0,
-      },
-    }))
-
-    const response = await c.host.describe({})
-    expect(response.result).toEqual({
-      ok: true,
-      value: {
-        version: 'v',
-        cwd: '/w',
-        attachedSessions: 0,
-      },
-    })
-  })
-
   it('round-trips the native picker without the default unary timeout', async () => {
     const api = fakeApi()
     api.host.pickDirectory = async (request) => {