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/web-react/src/index.ts

@@ -1,22 +1,15 @@
 /**
- * ctx-to-React machinery (slot terminal design §8): createSlotRenderer (the
+ * Shell-side React glue (slot terminal design §8): createSlotRenderer (the
  * install-seam implementation), SessionProvider (framework-wired render
- * prop), the defineStore shell, and useInvoke. Contract types (SlotRenderer
- * family, store family, four-share props) are ui-slots authority — this face
- * re-exports the ones its own values traffic in. The snapshot-store ENGINE
- * (createSnapshotStore) is framework-internal — runtime/i18n reach it through
- * the './store' subpath; business plugins declare stores via defineStore
- * only. React contexts stay in-package: business components see none.
+ * prop, also delivered as a standard seat to session-area entries),
+ * bindSnapshotSelector (the one hook constructor), and useInvoke. The
+ * snapshot-store engine and defineStore live in runtime (store relocation);
+ * contract types are ui-slots authority — this face re-exports only what its
+ * own values traffic in. React contexts stay in-package: business components
+ * see none.
  */
-import type { SnapshotSelectorHook } from './store/index.ts'
+import type { SnapshotSelectorHook } from '@deepseek-ai/dsh-client-ui-slots'
 
-// -- store: the declarative shell is public; the engine stays off this face --
-export type {
-  ActionsDecl, BakedActions, BoundActions, EngineStoreHandle, EngineStoreInstance,
-  ObservableSnapshot, SnapshotSelectorHook, SnapshotStore,
-  StoreFactory, StoreHandle, StoreInstance, StoreSpec,
-} from './store/index.ts'
-export { defineStore, shallowEqual } from './store/index.ts'
 export { bindSnapshotSelector } from './bind.ts'
 
 /**
@@ -29,7 +22,7 @@ export type UseSession<Snap extends object = object> = SnapshotSelectorHook<Snap
 
 // -- renderer: the install-seam implementation; contract lives in ui-slots --
 export type {
-  HostObservable, RenderOpts, SessionCell,
+  HostObservable, RenderOpts, SessionCell, SnapshotSelectorHook,
   SlotRenderer, SlotRendererHost, StoreInstanceLike,
 } from '@deepseek-ai/dsh-client-ui-slots'
 export { SlotOwnershipError, StaleAuthorizationError } from '@deepseek-ai/dsh-client-ui-slots'