refactor(gui): move the snapshot-store engine into the client runtime

The data layer no longer depends on the React glue package, and business
plugins no longer depend on web-react at all:

- The store engine (zustand vanilla + immer + persist + dev freeze),
  defineStore, and shallowEqual move to @deepseek-ai/dsh-client-runtime,
  exported from the ./client main entry — no ./store subpath survives on
  either package (the web-react one is deleted, none is opened on runtime).
- Store products are bare snapshot sources: useSelector leaves
  SnapshotStore/StoreInstance and Session; every hook is composed at the
  binding site in web-react's renderer (per-source cached uSES binding).
  The SlotRendererHost sessions face carries bare observables only.
- SessionProvider becomes a standard-kit seat: an entry whose children
  declare a session-scope slot receives the framework component as a prop,
  retiring the last value import of web-react from plugin packages.
  UseSession and the session-area types now live in ui-slots.
- web-react shrinks to the shell-only React glue (renderer, providers,
  uSES bridge); zustand/immer belong to runtime alone; the module-table
  seed and tsdown externals drop the web-react/store seat.
- NODE_ENV replacement is defined once in the shared tsdown client preset
  (browser bundles inline the engine and lost vite's define); the 3-line
  process.env typecheck shim moves to runtime with the engine.
- Stray tsc artifacts (.js/.d.ts/.d.ts.map beside sources under src/)
  swept repo-wide; they shadow real sources under vitest resolution.

Verified: both aggregate typecheck programs at zero; 604 client tests
green; repo-wide grep for web-react/store at zero; real-host playwright
run 7/7 including persist round-trip.

ci: fix test/docs

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

@@ -16,19 +16,33 @@ export interface HostObservable<T> {
 
 /**
  * Type-erased store instance face at the render seam (the typed twin is
- * {@link StoreInstance}): selector hook plus draft-stripped action callbacks.
- * Typing lands at the component seam via {@link PropsStore}.
+ * {@link StoreInstance}): a bare snapshot source plus the draft-stripped
+ * action callbacks. No React hook crosses this seam — the render machinery
+ * binds `useStore` from the source at its own side (cached per instance);
+ * typing lands at the component seam via {@link PropsStore}.
  */
 export interface StoreInstanceLike {
-  readonly useSelector: unknown
+  /** Current state snapshot (uSES getSnapshot side). */
+  getSnapshot(): unknown
+  /**
+   * Subscribe to state changes (uSES subscribe side).
+   * @param fn - change callback.
+   * @returns unsubscribe.
+   */
+  subscribe(fn: () => void): () => void
+  /** Baked write callbacks (delivered to components as `actions`). */
   readonly actions: Record<string, (...params: never[]) => void>
 }
 
 /** Session standard kit resolved per session id (identity-stable per session scope; a recreated scope yields a new cell). */
 export interface SessionCell {
   sessionId: string
-  /** Bound conversation-snapshot selector hook (wide here; runtime narrows at its export seam). */
-  useSession: unknown
+  /**
+   * Bare conversation-snapshot source (wide here; runtime narrows at its
+   * export seam). The React side binds the `useSession` hook per cell —
+   * hooks never appear on the host contract.
+   */
+  session: HostObservable<unknown>
 }
 
 /** renderSlot dispatch options at the machinery level: keyed dispatch key, list filtering, empty fallback. */