Merge remote-tracking branch 'origin/master' into worktree/web-multimodal-image-input

# Conflicts:
#	apps/cli/README.i18n.yaml
#	apps/cli/package.json
#	apps/cli/src/app-cli-entry.ts
#	apps/cli/src/args.ts
#	apps/cli/src/bin.ts
#	apps/cli/src/web.ts
#	apps/cli/tests/args.spec.ts
#	docs/architecture.i18n.yaml
#	docs/config-catalog.md
#	docs/module-graph.md
#	packages/README.i18n.yaml
#	packages/client/connection/README.i18n.yaml
#	packages/client/connection/src/client/api.ts
#	packages/client/connection/src/client/fixture.ts
#	packages/client/connection/src/index.ts
#	packages/client/connection/tests/node-half.spec.ts
#	packages/client/ui-conversation/README.i18n.yaml
#	packages/client/ui-conversation/src/client/chat/ChatView.tsx
#	packages/client/ui-conversation/src/client/skeleton/InputBar.tsx
#	packages/host/apiproxy/src/api/host.schema.ts
#	packages/host/apiproxy/src/index.ts
#	packages/ui/tui/README.i18n.yaml
#	pnpm-lock.yaml

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

@@ -57,6 +57,8 @@ function scriptedApi(overrides: {
     host: {
       describe: r => ok(r, { version: '0-test', cwd: '/t', attachedSessions: 0 }),
       pickDirectory: r => ok(r, { path: null }),
+      listDirectory: r => ok(r, { path: '/t', home: '/t', crumbs: [], entries: [], truncated: false }),
+      createDirectory: r => ok(r, { path: '/t/new' }),
       openPath: r => ok(r, { opened: true as const }),
       ...overrides.host,
     },
@@ -155,7 +157,7 @@ describe('unary round trip', () => {
   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: {} }
-    const response = await handler.fetch('http://dsh.internal/api/session.list', { method: 'POST', body: JSON.stringify(body) })
+    const response = await handler.fetch('http://dsh.internal/api/session.list', { method: 'POST', headers: { 'content-type': 'application/json' }, body: JSON.stringify(body) })
     expect(response.status).toBe(200)
     const parsed = await response.json() as { result: { ok: boolean; error?: { code: string; message: string } } }
     expect(parsed.result.ok).toBe(false)
@@ -166,13 +168,13 @@ describe('unary round trip', () => {
   it('rejects a malformed envelope as bad-request, salvaging the rpcId or falling back to the sentinel', async () => {
     const handler = toFetchHandler(scriptedApi())
     // No salvageable rpcId → the fixed invalid-request sentinel keeps the response a valid ServerResponse.
-    const noId = await handler.fetch('http://dsh.internal/api/session.list', { method: 'POST', body: JSON.stringify({ nonsense: true }) })
+    const noId = await handler.fetch('http://dsh.internal/api/session.list', { method: 'POST', headers: { 'content-type': 'application/json' }, body: JSON.stringify({ nonsense: true }) })
     expect(noId.status).toBe(200)
     const noIdParsed = await noId.json() as { rpcId: string; result: { ok: boolean } }
     expect(noIdParsed.result.ok).toBe(false)
     expect(noIdParsed.rpcId).toBe('invalid-request')
     // A string rpcId in the otherwise-bad body is salvaged for correlation.
-    const withId = await handler.fetch('http://dsh.internal/api/session.list', { method: 'POST', body: JSON.stringify({ rpcId: 'salvage-me', nonsense: true }) })
+    const withId = await handler.fetch('http://dsh.internal/api/session.list', { method: 'POST', headers: { 'content-type': 'application/json' }, body: JSON.stringify({ rpcId: 'salvage-me', nonsense: true }) })
     const withIdParsed = await withId.json() as { rpcId: string; result: { ok: boolean } }
     expect(withIdParsed.result.ok).toBe(false)
     expect(withIdParsed.rpcId).toBe('salvage-me')
@@ -181,16 +183,34 @@ describe('unary round trip', () => {
   it('maps carrier failures to HTTP statuses and the client throws transport failure', async () => {
     const handler = toFetchHandler(scriptedApi())
     // Unknown method → 404.
-    const notFound = await handler.fetch('http://dsh.internal/api/no.such', { method: 'POST', body: '{}' })
+    const notFound = await handler.fetch('http://dsh.internal/api/no.such', { method: 'POST', headers: { 'content-type': 'application/json' }, body: '{}' })
     expect(notFound.status).toBe(404)
     // Non-JSON body → 400.
-    const badBody = await handler.fetch('http://dsh.internal/api/session.list', { method: 'POST', body: '{oops' })
+    const badBody = await handler.fetch('http://dsh.internal/api/session.list', { method: 'POST', headers: { 'content-type': 'application/json' }, body: '{oops' })
     expect(badBody.status).toBe(400)
     // Impl crash → 500, and through the client that is a throw, not an err result.
     const crashing = scriptedApi({ sessions: { list: () => { throw new Error('impl exploded') } } })
     await expect(client(crashing).sessions.list({})).rejects.toThrow(/transport failure .*500/)
   })
 
+  it('rejects non-JSON media types before executing anything (cross-site simple-request fence)', async () => {
+    const list = vi.fn((r: RpcRequest<{}>) => ok(r, { items: [] }))
+    const handler = toFetchHandler(scriptedApi({ sessions: { list } }))
+    const body = JSON.stringify({ type: 'client-request', rpcId: 'r1', method: 'session.list', payload: {} })
+    // A "simple" browser POST (text/plain — sent with no CORS preflight) is
+    // refused at the carrier before the impl runs.
+    const plain = await handler.fetch('http://dsh.internal/api/session.list', { method: 'POST', headers: { 'content-type': 'text/plain' }, body })
+    expect(plain.status).toBe(415)
+    // A string body with no explicit header defaults to text/plain — same fence.
+    const unlabelled = await handler.fetch('http://dsh.internal/api/session.list', { method: 'POST', body })
+    expect(unlabelled.status).toBe(415)
+    expect(list).not.toHaveBeenCalled()
+    // Media-type parameters pass: the fence checks the type, not the exact string.
+    const charset = await handler.fetch('http://dsh.internal/api/session.list', { method: 'POST', headers: { 'content-type': 'application/json; charset=utf-8' }, body })
+    expect(charset.status).toBe(200)
+    expect(list).toHaveBeenCalledTimes(1)
+  })
+
   it('rejects when the transport never resolves within timeoutMs', async () => {
     // AbortSignal.timeout is immune to fake timers; a short real timeout keeps this fast.
     const never = new InProcessApiClient({
@@ -499,7 +519,7 @@ describe('respond path', () => {
   it('returns bad-response for a malformed client-response without reaching the impl', async () => {
     const respond = vi.fn()
     const handler = toFetchHandler(scriptedApi({ respond }))
-    const response = await handler.fetch('http://dsh.internal/api/respond', { method: 'POST', body: JSON.stringify({ type: 'client-response' }) })
+    const response = await handler.fetch('http://dsh.internal/api/respond', { method: 'POST', headers: { 'content-type': 'application/json' }, body: JSON.stringify({ type: 'client-response' }) })
     expect(await response.json()).toEqual({ accepted: false, reason: 'bad-response' })
     expect(respond).not.toHaveBeenCalled()
   })