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.

packages/client/modules/src/invariant.ts

@@ -0,0 +1,34 @@
+/**
+ * Package-owned invariant companion for `@deepseek-ai/dsh-client-modules`.
+ * @module @deepseek-ai/dsh-client-modules/invariant
+ */
+
+/* jscpd:ignore-start */
+import type { Context } from 'cordis'
+import type { InvariantInstaller } from '@deepseek-ai/dsh-invariants'
+
+const PACKAGE_NAME = '@deepseek-ai/dsh-client-modules'
+
+/** Cordis companion plugin name. */
+export const name = 'client-modules-invariant'
+/** Service required before the companion can reserve package ownership. */
+export const inject = ['invariants']
+
+/**
+ * No runtime invariant: the module loader is pre-plugin kernel machinery —
+ * it emits no cordis events (the vendored Loader owns entry lifecycle events)
+ * and its mutable state (loadCache, handoff slot) lives below the plugin
+ * layer where invariant observers cannot mount before it runs; resolve branch
+ * order and handoff discipline are asserted by the web boot specs against the
+ * real execution path.
+ */
+const install: InvariantInstaller = () => {}
+
+/**
+ * Register this package's invariant companion.
+ * @param ctx - Cordis context carrying the invariant service.
+ * @returns the installed registration's disposer after setup succeeds.
+ */
+export const apply = (ctx: Context): Promise<() => void> =>
+  Promise.resolve(ctx.invariants.register(PACKAGE_NAME, install))
+/* jscpd:ignore-end */