feat(web): add workspace-aware session flow

packages/client/ui-slots/README.md

@@ -13,7 +13,7 @@ One `register({ name, children?, store?, inject?, ...kind }, Component)` call co
 
 Chain-kind slots invert keyed routing — entries self-nominate instead of the dispatch site picking an `entryKey`: each registration carries a pure `ChainSelect` selector (plus optional ascending `priority`, ties in registration order), the first non-null return elects its entry and becomes the component's `matched` prop, and all-null falls to the owner's `renderSlotChain` fallback (`ChainRenderOpts`).
 
-The standard-kit interfaces (`SessionStandardProps`, `GlobalStandardProps`) are declared empty here and merged by the runtime package (same declare-merge pattern as SlotMap keys). Inject factory parameters derive from the declaration (`InjectParams`): session slots get `sessionId`, a declared store appends baked `actions`, nothing else — data access lives in the apply closure's ctx.
+The standard-kit interfaces (`SessionStandardProps`, `GlobalStandardProps`) are declared empty here and merged by the runtime package (same declare-merge pattern as SlotMap keys). The renderer binds the runtime's session and workspace observable sources into selector hooks. Inject factory parameters derive from the declaration (`InjectParams`): session slots get `sessionId`, a declared store appends baked `actions`, nothing else — data access lives in the apply closure's ctx.
 
 The store family (`defineStore` spec in / `StoreHandle<T, A>` out) types the store seat: `init` infers the state schema, `actions` is the complete draft-transform write set, `BakedActions` strips the draft parameter into the callbacks components and inject factories receive. The `defineStore` value implementation lives in the runtime package (the engine's home) and satisfies the `DefineStore` contract exported here. Engine products and the renderer host contract carry bare snapshot sources (`getSnapshot`/`subscribe`), never React hooks — hook binding is the render machinery's side of the seam; only the props-contract hook type (`SnapshotSelectorHook`) lives here.
 

packages/client/ui-slots/src/index.ts

@@ -74,8 +74,8 @@ export interface SessionStandardProps {}
 
 /**
  * Framework standard kit delivered to EVERY slot component (the global seat).
- * Declared empty here; the runtime package merges `useSessions` (the session
- * list selector hook — the sidebar tree's single derivation source).
+ * Declared empty here; the runtime package merges the global object-layer
+ * selector hooks that shared page composition consumes.
  */
 export interface GlobalStandardProps {}
 

packages/client/ui-slots/src/renderer.ts

@@ -98,6 +98,11 @@ export interface SlotRendererHost {
      */
     cell(id: string): SessionCell | undefined
   }
+  /** Workspace-side standard-kit sources. */
+  workspaces: {
+    /** Workspace list source backing the useWorkspaces standard hook. */
+    list: HostObservable<unknown>
+  }
 }
 
 /** The install seam: runtime owns install()/renderSlot(); web-react implements rendering. */