Merge remote-tracking branch 'origin/master' into feat/web-message-feedback-ui

Adapt to two contract changes master introduced:

- The generated Remote face now wraps every business result in
  RemoteResult, folding carrier failures into an ok:false branch instead
  of rejecting. The controller reads that envelope at its three call
  sites and maps a carrier failure onto the same settled shape the
  controls already render; three specs cover the new branch.
- Client packages split their tsconfig into host and client halves, and
  the host aggregate now compiles any test not named *.client.spec.*.
  Rename this package's specs to the client convention and drop the
  ../connection project reference, which pointed at a solution file that
  no longer carries the client sources.

Keep master's mount loop with its rollback-on-failure in api-remotes and
add messageFeedbackRemote to it.

packages/client/web-react/tests/use-projection.client.spec.tsx

@@ -0,0 +1,129 @@
+// @vitest-environment jsdom
+/**
+ * useProjection standard-kit delivery (session-projection subsystem page:
+ * docs/subsystems/session-projection.md): the fifth
+ * framework hook seat rides the same provide channel as useSession — a
+ * session slot component receives `useProjection` in its kit, key-addressed
+ * over the bundle's projection face; unresolved keys (no value, no face, no
+ * session) uniformly read `undefined`; live value changes re-render; the
+ * selector overload runs over the whole value.
+ */
+import { describe, expect, it } from 'vitest'
+import { act, render } from '@testing-library/react'
+import type { SessionMaybeProvideInfo, StoredEntry } from '@deepseek-ai/dsh-client-ui-slots'
+import { createSlotRenderer, type SlotRendererHost } from '@deepseek-ai/dsh-client-web-react'
+
+function observable<T>(initial: T) {
+  let value = initial
+  const subs = new Set<() => void>()
+  return {
+    getSnapshot: () => value,
+    subscribe: (fn: () => void) => { subs.add(fn); return () => { subs.delete(fn) } },
+    set: (next: T) => { value = next; for (const fn of [...subs]) fn() },
+  }
+}
+
+type UseProjectionProp = (key: string, selector?: (v: unknown) => unknown) => unknown
+
+function makeHost() {
+  const absentInfo: SessionMaybeProvideInfo = { sessionId: undefined, hooks: { session: undefined }, props: {} }
+  const provide = observable<SessionMaybeProvideInfo>(absentInfo)
+  const cells = new Map<string, ReturnType<typeof observable<unknown>>>()
+  /** Store-parallel face: always defined per key; an unseen key snapshots undefined. */
+  const absent = { getSnapshot: () => undefined, subscribe: () => () => {} }
+  const sessionEntries: StoredEntry[] = []
+  let withFace = true
+  const rootEntry: StoredEntry = {
+    component: (props: { renderSlot: (key: string, owner: object) => React.ReactNode }) =>
+      <>{props.renderSlot('k.session', {})}</>,
+    options: {},
+    children: { 'k.session': { kind: 'single', scope: 'session' } },
+  }
+  const info = (id: string): SessionMaybeProvideInfo => ({
+    sessionId: id,
+    hooks: { session: { getSnapshot: () => ({ sid: id }), subscribe: () => () => {} } },
+    props: {},
+    ...(withFace ? { projections: { faceOf: (key: string) => cells.get(key) ?? absent } } : {}),
+  })
+  const host: SlotRendererHost = {
+    subscribe: () => () => {},
+    getVersion: () => 0,
+    entriesOf: key => key === 'root' ? [rootEntry] : sessionEntries,
+    specOf: key => key === 'k.session' ? { kind: 'single', scope: 'session' } : undefined,
+    isLive: () => true,
+    storeOf: () => undefined,
+    sessions: {
+      list: observable<unknown>({ ids: [] }),
+      provideInfo: provide,
+    },
+    workspaces: { list: observable<unknown>({ items: [] }) },
+  }
+  return {
+    host,
+    cells,
+    // Same driver surface as before the atomic provide source: set(id)
+    // publishes the resolved bundle (or the absent projection) through it.
+    current: { set: (id: string | undefined) => { provide.set(id === undefined ? absentInfo : info(id)) } },
+    dropFace: () => { withFace = false },
+    registerSession: (entry: StoredEntry) => { sessionEntries.push(entry) },
+  }
+}
+
+describe('useProjection standard-kit delivery', () => {
+  it('reads the projected value through the kit, undefined for unresolved keys, and follows live changes', () => {
+    const h = makeHost()
+    const cell = observable<unknown>({ marks: ['a'] })
+    h.cells.set('test/marks', cell)
+    const reads: Record<string, unknown>[] = []
+    h.registerSession({
+      component: (props: { useProjection: UseProjectionProp }) => {
+        reads.push({
+          marks: props.useProjection('test/marks'),
+          ghost: props.useProjection('test/ghost'),
+        })
+        return null
+      },
+      options: {},
+    })
+    render(<>{createSlotRenderer().renderRoot(h.host, {})}</>)
+    act(() => { h.current.set('s1') })
+    expect(reads.at(-1)).toEqual({ marks: { marks: ['a'] }, ghost: undefined })
+    // Live change re-renders with the new whole value.
+    act(() => { cell.set({ marks: ['a', 'b'] }) })
+    expect(reads.at(-1)).toEqual({ marks: { marks: ['a', 'b'] }, ghost: undefined })
+  })
+
+  it('runs the selector overload over the whole value (and over undefined when absent)', () => {
+    const h = makeHost()
+    h.cells.set('test/marks', observable<unknown>({ marks: ['x', 'y'] }))
+    const reads: unknown[] = []
+    h.registerSession({
+      component: (props: { useProjection: UseProjectionProp }) => {
+        reads.push(props.useProjection('test/marks', v => (v as { marks: string[] } | undefined)?.marks.length ?? -1))
+        reads.push(props.useProjection('test/ghost', v => (v === undefined ? 'absent' : 'present')))
+        return null
+      },
+      options: {},
+    })
+    render(<>{createSlotRenderer().renderRoot(h.host, {})}</>)
+    act(() => { h.current.set('s1') })
+    expect(reads.slice(-2)).toEqual([2, 'absent'])
+  })
+
+  it('treats a bundle without the projections face as all-absent (capability absence)', () => {
+    const h = makeHost()
+    h.cells.set('test/marks', observable<unknown>({ marks: ['a'] }))
+    h.dropFace()
+    const reads: unknown[] = []
+    h.registerSession({
+      component: (props: { useProjection: UseProjectionProp }) => {
+        reads.push(props.useProjection('test/marks'))
+        return null
+      },
+      options: {},
+    })
+    render(<>{createSlotRenderer().renderRoot(h.host, {})}</>)
+    act(() => { h.current.set('s1') })
+    expect(reads.at(-1)).toBeUndefined()
+  })
+})