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/tsdown.config.ts

@@ -1,12 +1,12 @@
 import { defineConfig } from 'tsdown'
 
 /**
- * Root shape plus the store subpath, built as SEPARATE single-entry bundles:
- * a multi-entry build emits a hash-named shared chunk that the exact `files`
- * whitelist cannot publish (same shape as code-runtime-worker/user-approval).
- * Each entry inlines the shared store code instead; the node lib is the
- * repo-uniform shape (publint/NodeNext), not an identity-sensitive runtime —
- * browser consumers resolve this package through the loader module table.
+ * Root and invariant shapes as SEPARATE single-entry bundles: a multi-entry
+ * build emits a hash-named shared chunk that the exact `files` whitelist
+ * cannot publish (same shape as code-runtime-worker/user-approval). The node
+ * lib is the repo-uniform shape (publint/NodeNext), not an identity-sensitive
+ * runtime — browser consumers resolve this package through the loader module
+ * table.
  */
 export default defineConfig([
   {
@@ -29,14 +29,4 @@ export default defineConfig([
     dts: false,
     clean: false,
   },
-  {
-    entry: { 'store/index': 'lib/types/store/index.js' },
-    outDir: 'lib',
-    format: ['esm'],
-    platform: 'neutral',
-    target: 'es2024',
-    fixedExtension: false,
-    dts: false,
-    clean: false,
-  },
 ])