feat(web): make dsh-client-modules dual-face with an incremental host scan

The node half is ClientModuleHostService (ctx.clientModuleHost): it composes
the __DSH_BOOT__ graph by scanning loader entries for dshClient packages,
serves /plugins/<id>/client.js, taps the index render, and exposes
rebuilt/onRebuilt/onGraphChanged. Scanning is incremental per package — no
full-rescan path exists: internal/plugin marks the fiber's entry name dirty,
a flush reconciles each name against live entries, package metadata
(including negative verdicts) caches forever, and re-hashing is reachable
only through rebuilt(id). The browser half moves wholesale to the standard
./client export (ClientModuleSystem, parseBootManifest with the dual-view
BootManifest, and the adoption plugin face that reads the
window.__DSH_MODULES__ slot and provides ctx.modules).

packages/client/modules/src/client/manifest.ts

@@ -0,0 +1,243 @@
+/**
+ * Client module system: the browser peer of Node's internal ESM loader, built
+ * as a lazy CJS table. The vendored cordis Loader consumes this object
+ * through its `internal` seam (the only call site is `EntryTree.import` →
+ * `internal.import`), which keeps entry governance (fiber lifecycle, inject
+ * waiting, update/refresh) entirely on the vendored side while this package
+ * owns code arrival.
+ *
+ * Lazy CJS model (web2 §0): executing a plugin bundle only REGISTERS its
+ * factory (`window.__ModuleLoader__.load({id, factory})`); every module body
+ * side effect — including CSS injection — lives inside the factory closure
+ * and runs at materialization, not at script execution. Materialization
+ * (factory(require) → export surface) happens on first import/require and is
+ * memoized in {@link ClientModuleLoader.loadCache}; a factory that requires
+ * another registered-but-unmaterialized module materializes it recursively,
+ * so load order needs no external sequencing.
+ *
+ * Resolution branch order (import): seed word → shell instance; memoized
+ * record → surface; static registry (shell-own modules, e.g. app-shell) →
+ * module; registered factory → materialize; graph row → fetch + execute +
+ * materialize; anything else → throw (loud — the runtime mirror of the
+ * build-time bundle purity gate). The synchronous `require` handed to
+ * factories walks the same order minus the fetch branch: fetching is async,
+ * so only already-executed bundles can be required — and cross-plugin value
+ * imports are a build error anyway.
+ *
+ * This file is the browser-safe contract face (zero node imports): the
+ * `__DSH_BOOT__` wire types, the boot-manifest parser, and the seams around
+ * {@link ClientModuleSystem}. The package root is the host-side service that
+ * composes the wire.
+ */
+
+import type {} from 'cordis'
+import type { ClientModuleSystem } from './system.ts'
+
+declare module 'cordis' {
+  interface Context {
+    /** The client module system the web shell builds at boot (contract C5; provided by the `./client` wrapper plugin). */
+    modules: ClientModuleLoader
+  }
+}
+
+/**
+ * One composed client entry pushed by the host (web2 §0 graph row). Wire
+ * single source: the host node half (package root) produces this same shape.
+ * `immediately` marks stage-one prefetch; `inject` is informational graph
+ * metadata (the authoritative edges live in each package's dshClient
+ * declaration and reach fibers through entry creation).
+ */
+export interface WebBootEntry {
+  /** Entry name == package name. */
+  id: string
+  /** Bundle endpoint, '/plugins/<id>/client.js?rev=<rev>'. */
+  url: string
+  /** Bundle content hash (cache-busting consistency anchor). */
+  rev: string
+  /** Package-name dependency edges, informational (preflight display / HMR diffing). */
+  inject?: string[]
+  /** Stage-one prefetch mark: fetch + execute (factory registration) during module-face boot. */
+  immediately?: boolean
+}
+
+/** The composed client entry graph the host injects as `window.__DSH_BOOT__`. */
+export interface WebBootGraph {
+  /** Consistency anchor over the whole graph (content + bundle hashes). */
+  rev: string
+  /** Composed entries; order carries no semantics (activation order is fiber inject waiting). */
+  entries: WebBootEntry[]
+}
+
+/** The npm-package view of one boot row: what the module table needs to fetch the bundle. */
+export interface BootModuleRow {
+  /** Entry name == package name (module-table key). */
+  id: string
+  /** Bundle endpoint, '/plugins/<id>/client.js?rev=<rev>'. */
+  url: string
+  /** Bundle content hash. */
+  rev: string
+}
+
+/** The cordis-plugin view of one boot row: what entry composition needs (optional wire fields normalized). */
+export interface BootPluginRow {
+  /** Entry name == package name. */
+  id: string
+  /** Package-name dependency edges ([] when the wire omits them). */
+  inject: string[]
+  /** Stage-one prefetch tier (false when the wire omits it). */
+  immediately: boolean
+}
+
+/** The parsed boot manifest: one wire, two consumer views. */
+export interface BootManifest {
+  /** Consistency anchor over the whole graph. */
+  rev: string
+  /** Rows as the module table consumes them. */
+  modules: BootModuleRow[]
+  /** Rows as entry composition consumes them. */
+  plugins: BootPluginRow[]
+}
+
+/**
+ * Parse `window.__DSH_BOOT__` into the two consumer views. Wire boundary:
+ * a missing or malformed graph throws (the shell shows the loud failure —
+ * a page without a valid manifest cannot boot anything).
+ * @param wire - the raw `window.__DSH_BOOT__` value.
+ * @returns the manifest with optional plugin-view fields normalized.
+ */
+export function parseBootManifest(wire: unknown): BootManifest {
+  if (typeof wire !== 'object' || wire === null) {
+    throw new Error('client-modules: window.__DSH_BOOT__ is missing or not an object')
+  }
+  const graph = wire as Record<string, unknown>
+  if (typeof graph.rev !== 'string') {
+    throw new Error('client-modules: boot manifest rev must be a string')
+  }
+  if (!Array.isArray(graph.entries)) {
+    throw new Error('client-modules: boot manifest entries must be an array')
+  }
+  const modules: BootModuleRow[] = []
+  const plugins: BootPluginRow[] = []
+  for (const value of graph.entries as unknown[]) {
+    if (typeof value !== 'object' || value === null) {
+      throw new Error('client-modules: boot manifest entry is not an object')
+    }
+    const row = value as Record<string, unknown>
+    const where = typeof row.id === 'string' ? `"${row.id}"` : JSON.stringify(row)
+    if (typeof row.id !== 'string' || typeof row.url !== 'string' || typeof row.rev !== 'string') {
+      throw new Error(`client-modules: boot manifest entry ${where} must carry string id/url/rev`)
+    }
+    if (row.inject !== undefined && (!Array.isArray(row.inject) || row.inject.some(i => typeof i !== 'string'))) {
+      throw new Error(`client-modules: boot manifest entry ${where} inject must be a string array`)
+    }
+    if (row.immediately !== undefined && typeof row.immediately !== 'boolean') {
+      throw new Error(`client-modules: boot manifest entry ${where} immediately must be a boolean`)
+    }
+    modules.push({ id: row.id, url: row.url, rev: row.rev })
+    plugins.push({
+      id: row.id,
+      inject: row.inject === undefined ? [] : [...row.inject as string[]],
+      immediately: row.immediately === true,
+    })
+  }
+  return { rev: graph.rev, modules, plugins }
+}
+
+/** The shape a client bundle hands to `window.__ModuleLoader__.load` (registration handoff, contract C6). */
+export interface ClientPluginHandoff {
+  /** Plugin id (package name) — the registration key; must match the graph row being executed. */
+  id: string
+  /**
+   * Closure factory holding the whole bundle body: receives the synchronous
+   * require bound to the module table and returns the bundle's export
+   * surface. Runs once, at materialization.
+   */
+  factory: (require: (spec: string) => unknown) => Record<string, unknown>
+}
+
+/** Window surface of the web boot protocol: the host-injected graph, the registration sink, and the kernel handoff slot. */
+export interface DshWindow {
+  /** Host-composed entry graph, injected before the shell bundle runs; wire-boundary raw until {@link parseBootManifest}. */
+  __DSH_BOOT__?: unknown
+  /** Bundle registration sink; installed once per page by the {@link ClientModuleSystem} constructor (contract C6). */
+  __ModuleLoader__?: { load(handoff: ClientPluginHandoff): void }
+  /**
+   * Kernel handoff slot: the shell kernel stores the instance here right
+   * after construction (before cordis exists) so the `./client` wrapper
+   * plugin can provide it as `ctx.modules`. Missing slot at wrapper apply
+   * time = kernel sequencing bug, thrown loud.
+   */
+  __DSH_MODULES__?: ClientModuleSystem
+}
+
+/** Per-module bookkeeping in {@link ClientModuleLoader.loadCache} (module-graph seam, flat today). */
+export interface ClientModuleRecord {
+  /** Module id (entry name / package name). */
+  id: string
+  /** The materialized export surface (factory `module.exports`, or the shell module for static registrations). */
+  surface: unknown
+  /** Owned `<style data-plugin>` tag ids (`data-plugin-css` values) injected during materialization. */
+  styles: string[]
+  /** Observed `require()` edges (module-graph seam; only table words can appear today). */
+  edges: Set<string>
+}
+
+/**
+ * The internal-seam subset the vendored Loader and the client HMR plugin
+ * consume. Mounted on `ctx.loader.internal` by the shell boot and provided
+ * as `ctx.modules` (contract C5).
+ */
+export interface ClientModuleLoader {
+  /** Discriminant against Node's internal loader shapes ('v1'/'v2'). */
+  version: 'client'
+  /** Materialized-module registry: id → record. The governance-side read face for entry export surfaces. */
+  loadCache: Map<string, ClientModuleRecord>
+  /**
+   * Internal seam consumed by the vendored Loader's `tree.import`. Resolves
+   * `specifier` through the branch order documented on the module, fetching
+   * and executing a bundle when needed.
+   * @param specifier - module specifier (entry name or table word).
+   * @param parentURL - importer URL (unused — the client module graph is flat).
+   * @param attrs - import attributes (unused; interface parity with Node's seam).
+   * @returns the module's export surface.
+   */
+  import(specifier: string, parentURL: string, attrs: Record<string, unknown>): Promise<unknown>
+  /**
+   * Register a shell-own module (app-shell — code that ships inside the shell
+   * bundle and never arrives as a plugin bundle).
+   * @param id - entry name (shell-owned pseudo id).
+   * @param module - the statically imported module namespace.
+   */
+  registerStatic(id: string, module: unknown): void
+  /**
+   * Stage-one arrival: fetch the entry's bundle and execute it, registering
+   * its factory (no materialization — module side effects wait for import).
+   * No-op for static-registered ids and ids whose factory is already
+   * registered; concurrent calls share one in-flight task. To force a fresh
+   * fetch (HMR), {@link invalidate} first.
+   * @param id - graph entry name.
+   */
+  prefetch(id: string): Promise<void>
+  /**
+   * Full reset of one module: drop its registered factory, its materialized
+   * record, and any consumed bundle text, so the next prefetch/import
+   * refetches and re-executes (the HMR invalidation hook).
+   * @param id - entry name to invalidate.
+   */
+  invalidate(id: string): void
+}
+
+/** Options for {@link ClientModuleSystem} (assembled by the web shell kernel at boot). */
+export interface ClientModuleSystemOptions {
+  /** Boot rows in the module-table view (from {@link parseBootManifest}). */
+  modules: BootModuleRow[]
+  /** Module-table seed: platform-singleton specifier → shell instance. */
+  staticModules: Record<string, unknown>
+  /** Bundle fetch seam (parallelizable half). Defaults to same-origin fetch().text(). */
+  fetchBundle?: (url: string) => Promise<string>
+  /**
+   * Bundle execution seam (synchronously performs the load() registration).
+   * Defaults to a <script> element carrying the code.
+   */
+  executeBundle?: (code: string, url: string) => void
+}