fix(client): load plugin bundles as external scripts

packages/client/tsdown.client.ts

@@ -9,7 +9,8 @@
  * The virtual loader registers each real stylesheet as a watch dependency.
  */
 import { readFile } from 'node:fs/promises'
-import { basename, dirname, resolve as resolvePath } from 'node:path'
+import { basename, dirname, relative, resolve as resolvePath, sep } from 'node:path'
+import { fileURLToPath } from 'node:url'
 import type { UserConfig } from 'tsdown'
 import { transform } from 'lightningcss'
 import { PLATFORM_MODULES } from './web/src/platform.ts'
@@ -45,6 +46,16 @@ const RUNTIME_STORE_EXEMPTION = '@deepseek-ai/dsh-client-runtime/client'
 /** Externals resolved from the loader module table: the platform seed entries plus the documented runtime exemption. */
 export const CLIENT_EXTERNALS: readonly string[] = [...PLATFORM_MODULES, RUNTIME_STORE_EXEMPTION]
 
+const REPOSITORY_ROOT = fileURLToPath(new URL('../..', import.meta.url))
+
+/** Rebase a physical lib-relative source onto the browser's repository-shaped URL tree. */
+function browserSourcePath(source: string, sourcemapPath: string): string {
+  if (!source.startsWith('.')) return source
+  const physicalSource = resolvePath(dirname(sourcemapPath), source)
+  const repositoryPath = relative(REPOSITORY_ROOT, physicalSource).split(sep).join('/')
+  return repositoryPath.startsWith('packages/') ? `../../../${repositoryPath}` : source
+}
+
 /**
  * Build the tsdown config for one UI plugin package: the node-half lib build
  * plus the browser client bundle. A package-level tsdown.config.ts REPLACES
@@ -78,6 +89,9 @@ export function clientBundle(id: string, libEntry: readonly string[]): UserConfi
     platform: 'browser',
     // Types ship from lib/types (tsc); dts here would wrap the banner/footer into .d.cts and break parsing.
     dts: false,
+    // Plugin code is fetched outside Vite's module graph, so its own bundle
+    // must carry the TS/TSX mapping consumed by browser profiling tools.
+    sourcemap: true,
     clean: false,
     external: [...CLIENT_EXTERNALS],
     // Browser bundles inline node-idiom deps (zustand/immer read
@@ -156,6 +170,11 @@ export function clientBundle(id: string, libEntry: readonly string[]): UserConfi
     }],
     outputOptions: {
       entryFileNames: 'client.js',
+      // The map is served from /plugins/<scoped-package>/client.js.map. The
+      // browser resolves its local sources back into the repository-shaped
+      // /packages/<group>/<package>/src tree; sourcesContent keeps them usable
+      // without exposing that tree as an HTTP route.
+      sourcemapPathTransform: browserSourcePath,
       banner: `window.__ModuleLoader__.load({ id: ${JSON.stringify(id)}, factory: (require) => {`,
       footer: `return module.exports; } });`,
       intro: 'var module = { exports: {} }; var exports = module.exports;',