refactor(gui): rebuild the client loading kernel as dsh-client-modules with a two-phase boot

The module system moves out of dsh-client-runtime (./loader retired) into
its own package: a lazy CJS table where executing a bundle only registers
its factory and materialization happens at first require, memoized, with
recursive requires self-ordering. ClientModuleSystem is a class; index.ts
keeps the types and a thin factory. Boot is two-phase: phase one prefetches
the immediately tier in parallel (registration only, failures deferred to
phase two's loud import); phase two mounts the vendored Loader with the
module system as internal, creates one entry per graph row plus the
app-shell pseudo-row the kernel appends itself, and settles on an
all-ACTIVE sweep. The shell kernel is self-sufficient: hand-rolled
loader-status stores, no plugin value imports, platform seed list single-
sourced in platform.ts.

apps/web/src/node-module-stub.ts

@@ -0,0 +1,16 @@
+/**
+ * Browser stand-in for `node:module`, mapped by the vite alias in
+ * vite.config.ts (design §2.4). The vendored Loader's internal.ts imports
+ * `createRequire` at module scope but only calls it inside
+ * `ModuleLoader.fromInternal()`, whose version probe is compiled to the
+ * `"0.0.0"` define in the browser build — so this throw is a fail-loud
+ * tripwire for any path that would genuinely need Node's module machinery.
+ */
+
+/** Throwing stand-in for node:module's createRequire (never reached in the browser boot). */
+export const createRequire = (): never => {
+  throw new Error('node:module is not available in the browser')
+}
+
+/** Erased type peer for the vendored loader's type-only LoadHookContext import. */
+export type LoadHookContext = never