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/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@deepseek-ai/dsh-client-web-react",
-  "description": "ctx-to-React glue: createSnapshotStore (zustand engine), bindSnapshotSelector, SessionProvider, scopedSlots outlet, useInvoke",
+  "description": "Shell-side React glue: createSlotRenderer, SessionProvider, bindSnapshotSelector (uSES bridge), useInvoke",
   "version": "0.0.1",
   "private": true,
   "type": "module",
@@ -15,20 +15,14 @@
       "types": "./lib/types/invariant.d.ts",
       "default": "./lib/invariant.js"
     },
-    "./store": {
-      "types": "./lib/types/store/index.d.ts",
-      "default": "./lib/store/index.js"
-    },
     "./src/*": "./src/*",
     "./package.json": "./package.json"
   },
   "license": "BSD-3-Clause",
   "dependencies": {
     "@deepseek-ai/dsh-client-ui-slots": "workspace:^",
-    "immer": "^10.1.1",
     "react": "^18.2.0",
-    "use-sync-external-store": "1.2.0",
-    "zustand": "~4.4.7"
+    "use-sync-external-store": "1.2.0"
   },
   "peerDependencies": {
     "@deepseek-ai/dsh-invariants": "^0.0.1",
@@ -42,7 +36,6 @@
   "files": [
     "lib/index.js",
     "lib/invariant.js",
-    "lib/store/index.js",
     "lib/types/**/*.d.ts",
     "lib/types/**/*.d.ts.map",
     "src"