Merge remote-tracking branch 'origin/master' into worktree/web-session-titles

# Conflicts:
#	.agents/notes/implemented/process/2026-07-20-gui-testing-system.i18n.yaml
#	packages/client/ui-conversation/tests/apply-inject.spec.tsx
#	packages/client/ui-conversation/tests/chat-stats-bash-sample.spec.tsx
#	packages/client/ui-conversation/tests/gate-branch-tails.spec.tsx
#	packages/client/ui-conversation/tests/selection-survival.spec.ts
#	packages/client/ui-conversation/tests/skeleton-branches.spec.tsx
#	packages/client/ui-conversation/tests/skeleton.spec.tsx
#	packages/client/ui-layout/tests/service.spec.ts
#	packages/client/ui-sidebar/tests/apply.spec.tsx
#	packages/client/ui-sidebar/tests/store.spec.ts
#	packages/client/ui-trajectory/tests/views.spec.tsx
#	packages/client/web/src/app.tsx
#	packages/client/web/tests/boot.spec.tsx
#	packages/host/runtime/README.md
#	packages/host/runtime/tests/host-runtime.spec.ts

packages/host/runtime/tests/host-runtime.spec.ts

@@ -1,4 +1,4 @@
-import { mkdtempSync } from 'node:fs'
+import { mkdirSync, mkdtempSync, writeFileSync } from 'node:fs'
 import { tmpdir } from 'node:os'
 import { join } from 'node:path'
 import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
@@ -17,6 +17,8 @@ import { bootHost, startHost, type HostHandle, type RunningHost } from '../src/i
 
 /** Scripted adapter: each model call consumes the next chunk list; 'hang' streams then waits for abort. */
 class ScriptedAdapter extends LlmAdapter {
+  readonly requests: GenerateOptions[] = []
+
   constructor(private script: (StreamChunk[] | 'hang')[]) {
     super()
   }
@@ -26,6 +28,7 @@ class ScriptedAdapter extends LlmAdapter {
       yield * textResponse('Durable append-only session titles')
       return
     }
+    this.requests.push(options)
     const entry = this.script.shift()
     if (!entry) throw new Error('ScriptedAdapter: script exhausted')
     if (entry === 'hang') {
@@ -106,6 +109,7 @@ async function boot(
   host = await startHost({
     boot: {
       persistenceRoot: mkdtempSync(join(tmpdir(), 'dsh-host-runtime-')),
+      workspaceContext: false,
       provider: 'scripted',
       model: 'test-model',
       ...(sessionTitle === undefined ? {} : { sessionTitle }),
@@ -118,7 +122,10 @@ async function boot(
 
 describe('bootHost / startHost', () => {
   it('falls back to the deepseek defaults and disposes idempotently', async () => {
-    const handle: HostHandle = await bootHost({ persistenceRoot: mkdtempSync(join(tmpdir(), 'dsh-boot-')) })
+    const handle: HostHandle = await bootHost({
+      persistenceRoot: mkdtempSync(join(tmpdir(), 'dsh-boot-')),
+      workspaceContext: false,
+    })
     expect(handle.defaults).toMatchObject({ provider: 'deepseek', model: 'deepseek-v4-flash' })
     expect(typeof handle.defaults.cwd).toBe('string')
     await handle.dispose()
@@ -136,6 +143,41 @@ describe('bootHost / startHost', () => {
     await first
     host = undefined
   })
+
+  it('routes workspace instructions through the assembled agent request prefix', async () => {
+    const workspace = mkdtempSync(join(tmpdir(), 'dsh-host-workspace-'))
+    mkdirSync(join(workspace, '.git'))
+    writeFileSync(join(workspace, 'AGENTS.md'), 'host-workspace-context-probe\n')
+    const adapter = new ScriptedAdapter([textResponse('done')])
+    host = await startHost({
+      boot: {
+        persistenceRoot: mkdtempSync(join(tmpdir(), 'dsh-host-workspace-sessions-')),
+        workspaceContext: { dshHome: join(workspace, '.dsh'), maxBytes: 65_536 },
+        provider: 'scripted',
+        model: 'test-model',
+        cwd: workspace,
+      },
+    })
+    host.ctx.llm.registerAdapter(['scripted'], adapter)
+    const { sessionId } = expectOk(await host.api.sessions.create(request({})))
+    const agent = host.ctx.agents.get(sessionId) as Agent
+    const idle = waitForIdle(host.ctx, agent)
+
+    expectOk(await host.api.sessions.prompt(request({
+      sessionId,
+      mode: 'queue' as const,
+      content: [{ type: 'text' as const, text: 'go' }],
+    })))
+    await idle
+
+    const requestText = adapter.requests[0]?.messages
+      .flatMap(message => message.content)
+      .filter(block => block.type === 'text')
+      .map(block => block.text)
+      .join('\n') ?? ''
+    expect(requestText).toContain('Instructions from: AGENTS.md')
+    expect(requestText).toContain('host-workspace-context-probe')
+  })
 })
 
 describe('host.describe', () => {
@@ -315,7 +357,9 @@ describe('sessions.prompt / cancel', () => {
 describe('sessions.history', () => {
   it('implicitly resumes a cold session, deduplicating concurrent calls to one attach', async () => {
     const persistenceRoot = mkdtempSync(join(tmpdir(), 'dsh-host-resume-'))
-    const first = await startHost({ boot: { persistenceRoot, provider: 'scripted', model: 'test-model' } })
+    const first = await startHost({
+      boot: { persistenceRoot, workspaceContext: false, provider: 'scripted', model: 'test-model' },
+    })
     first.ctx.llm.registerAdapter(['scripted'], new ScriptedAdapter([textResponse('persisted')]))
     const { sessionId } = expectOk(await first.api.sessions.create(request({})))
     const agent = first.ctx.agents.get(sessionId) as Agent
@@ -325,7 +369,9 @@ describe('sessions.history', () => {
     const titleEvent = await appendTitle(first.ctx, agent, 'Persisted title')
     await first.dispose()
 
-    host = await startHost({ boot: { persistenceRoot, provider: 'scripted', model: 'test-model' } })
+    host = await startHost({
+      boot: { persistenceRoot, workspaceContext: false, provider: 'scripted', model: 'test-model' },
+    })
     host.ctx.llm.registerAdapter(['scripted'], new ScriptedAdapter([]))
     expect(host.ctx.agents.get(sessionId)).toBeUndefined()
     const abort = new AbortController()