refactor(picker): split the directory-picker faces into their own packages

The browse and native backends were dual-face packages: a Node backend plus a
browser surface under one tsconfig that referenced Client packages. That put
Client projects — and through them the Client runtime — inside the Host
compiler aggregate, which builds before the generated Remote contributions
exist. Each browser half moves to its own Client package, and both backends
become Node-only.

The interaction is still one choice: the adaptive chooser mounts the backend
and its surface as a pair of Loader entries and tears both down in reverse, so
a resolved kind still swaps both faces. Compositions that pin an interaction
directly now pin the pair, and the chooser's runtime-string package list keeps
naming everything a composing app must resolve.

packages/host/directory-picker-auto/src/index.ts

@@ -1,12 +1,13 @@
 /**
  * Adaptive chooser of the directory-picker seam: resolves the host's
  * situation once at boot (bind host, SSH launch, display session, Linux
- * chooser binary) and mounts the matching dual-face backend — `-native` or
- * `-browse` — as a real Loader entry in the in-memory root tree. Because the
- * backend arrives as an ordinary entry, its browser half is discovered
- * exactly as a config-row's would be, so the seam's one-row-swaps-both-faces
- * invariant holds for the resolved choice; pinning an interaction remains
- * composing that backend row directly instead of this one.
+ * chooser binary) and mounts the matching interaction — `native` or `browse`
+ * — as real Loader entries in the in-memory root tree. Each interaction is a
+ * pair: the Host backend serving the seam capability and the client surface
+ * occupying ui-workspace's directory-flow holes. Both arrive as ordinary
+ * entries, so the surface is discovered exactly as a config-row's would be
+ * and one resolved choice still swaps both faces; pinning an interaction
+ * remains composing that pair directly instead of this row.
  * @module @deepseek-ai/dsh-host-directory-picker-auto
  */
 
@@ -28,7 +29,7 @@ export const name = 'directory-picker-auto'
 export const inject = ['httpServer', 'loader']
 
 /**
- * Backend package per resolved kind — fixed composition vocabulary, not a
+ * Host backend package per resolved kind — fixed composition vocabulary, not a
  * tunable. Exported because the reference is a runtime string the static
  * config gate cannot see in a yml row: `verify-cordis-config` requires every
  * app composing this chooser to declare both values as dependencies.
@@ -39,10 +40,20 @@ export const BACKEND_PACKAGES: Record<DirectoryPickerBackendKind, string> = {
 }
 
 /**
- * Resolve the backend from one boot-time sample and mount it as a Loader
- * entry; the effect's disposer removes the entry and joins the backend
- * fiber's teardown, so unloading this plugin returns only after both faces
- * of the mounted backend (and their dependents) quiesced.
+ * Client surface package per resolved kind, mounted with its backend so one
+ * resolved interaction still composes both faces. Declared as dependencies by
+ * every composing app for the same reason as {@link BACKEND_PACKAGES}.
+ */
+export const SURFACE_PACKAGES: Record<DirectoryPickerBackendKind, string> = {
+  native: '@deepseek-ai/dsh-client-ui-directory-picker-native',
+  browse: '@deepseek-ai/dsh-client-ui-directory-picker',
+}
+
+/**
+ * Resolve the interaction from one boot-time sample and mount its backend and
+ * surface as Loader entries; the effect's disposer removes both entries and
+ * joins their fibers' teardown, so unloading this plugin returns only after
+ * both faces of the mounted interaction (and their dependents) quiesced.
  * @param ctx - cordis context carrying the injected `httpServer` and `loader`.
  */
 export async function apply(ctx: Context): Promise<void> {
@@ -54,16 +65,22 @@ export async function apply(ctx: Context): Promise<void> {
   })
   await ctx.effect(async () => {
     // Root-tree create: the Loader root is in-memory (write() is a no-op), so
-    // the mounted row can never be persisted back into a config file.
-    const id = await ctx.loader.create({ name: BACKEND_PACKAGES[backend] })
-    return async () => {
-      // Tree teardown (group.stop) can have removed the entry already;
-      // nothing is left to unmount or await then.
-      const entry = ctx.loader.store[id]
-      if (entry === undefined) return
-      // remove() disposes the entry transactionally, so the chooser's unload
-      // signals completion only after the backend quiesced.
-      await ctx.loader.remove(id)
+    // the mounted rows can never be persisted back into a config file. The
+    // backend lands first: the surface's browser half drives the capability
+    // the backend registers.
+    const ids: string[] = []
+    for (const name of [BACKEND_PACKAGES[backend], SURFACE_PACKAGES[backend]]) {
+      ids.push(await ctx.loader.create({ name }))
     }
-  }, 'directory-picker-auto: backend entry')
+    return async () => {
+      for (const id of ids.reverse()) {
+        // Tree teardown (group.stop) can have removed the entry already;
+        // nothing is left to unmount or await then.
+        if (ctx.loader.store[id] === undefined) continue
+        // remove() disposes the entry transactionally, so the chooser's unload
+        // signals completion only after that face quiesced.
+        await ctx.loader.remove(id)
+      }
+    }
+  }, 'directory-picker-auto: interaction entries')
 }