feat(web): add workspace-aware session flow

packages/client/runtime/tests/slots-service.spec.ts

@@ -85,11 +85,18 @@ function captureHost(bench: Bench, children?: object): SlotRendererHost {
   })
   bench.erased.register({ name: 'root', ...(children !== undefined ? { children } : {}) }, C)
   bench.ctx.reflect.provide('sessions', fakeSessions())
+  bench.ctx.reflect.provide('workspaces', fakeWorkspaces())
   bench.erased.renderSlot('root', {})
   if (host === undefined) throw new Error('renderer never received the host')
   return host
 }
 
+/** Minimal independent Workspace list source for the renderer host seam. */
+function fakeWorkspaces() {
+  const state = { items: [], phase: 'ready' as const }
+  return { list: { getSnapshot: () => state, subscribe: () => () => undefined } }
+}
+
 /** Minimal sessions face for the host seam (list observable + cell). */
 function fakeSessions() {
   const state = { ids: [], byId: {}, current: undefined as string | undefined }
@@ -190,9 +197,18 @@ describe('renderer install seam', () => {
     bench.erased.install({ renderRoot })
     bench.erased.register({ name: 'root' }, C)
     bench.ctx.reflect.provide('sessions', fakeSessions())
+    bench.ctx.reflect.provide('workspaces', fakeWorkspaces())
     expect(bench.erased.renderSlot('root', {})).toBe('tree')
     expect(renderRoot).toHaveBeenCalledTimes(1)
   })
+
+  it('fails before rendering when the Workspace object layer is absent', async () => {
+    const bench = await boot()
+    bench.erased.install({ renderRoot: () => null })
+    bench.erased.register({ name: 'root' }, C)
+    bench.ctx.reflect.provide('sessions', fakeSessions())
+    expect(() => bench.erased.renderSlot('root', {})).toThrow(/workspaces service mounted/)
+  })
 })
 
 describe('host face', () => {
@@ -220,6 +236,12 @@ describe('host face', () => {
     expect(host.sessions.cell('known')).toMatchObject({ sessionId: 'known' })
     expect(host.sessions.cell('ghost')).toBeUndefined()
   })
+
+  it('exposes the independent Workspace list source', async () => {
+    const bench = await boot()
+    const host = captureHost(bench)
+    expect(host.workspaces.list.getSnapshot()).toEqual({ items: [], phase: 'ready' })
+  })
 })
 
 describe('store instance axis', () => {
@@ -315,6 +337,7 @@ describe('entry-unload cascade', () => {
       renderRoot: (h: SlotRendererHost) => { host = h; return 'rendered' },
     })
     bench.ctx.reflect.provide('sessions', fakeSessions())
+    bench.ctx.reflect.provide('workspaces', fakeWorkspaces())
     // The declarer here is NOT the root occupant: root stays occupied by a
     // separate entry so disposing the declarer only kills its children.
     const disposeRoot = bench.erased.register({ name: 'root' }, C)