Let plugins add contextual workspace tools (#3465)

* feat(plugins): add workspace panels and command center contributions

Give local plugins contextual UI entry points without making the daemon interpret client placement or callbacks. Panels receive stable IDs and read cached client state through required selectors with shallow equality, avoiding unrelated guest rerenders and context-discovery RPCs.

* fix(plugins): align shared client state ownership

Workspace panels and Command Center callbacks consume the same frozen client snapshots, so their adapter belongs to the plugin boundary rather than either contribution surface. Refresh the Nix dependency hash for the selector-store dependency added by this feature.

public-docs/plugins/index.md

@@ -1,6 +1,6 @@
 ---
 title: Plugin quickstart
-description: Build, install, and reload a trusted local Paseo plugin with a native sidebar surface.
+description: Build, install, and reload a trusted local Paseo plugin with a workspace panel.
 nav: Quickstart
 order: 45
 category: Plugins
@@ -8,7 +8,7 @@ category: Plugins
 
 # Plugin quickstart
 
-Paseo plugins add native surfaces, sidebar items, daemon behavior, and composer attachment sources. They run on every Paseo client connected to the host, including mobile.
+Paseo plugins add native workspace panels, Command Center items, global surfaces, daemon behavior, and composer attachment sources. They run on every Paseo client connected to the host, including mobile.
 
 Plugins are trusted local code. Install only code you trust: backend code runs unsandboxed with access to the daemon machine, and client contributions run inside the Paseo app.
 
@@ -27,8 +27,8 @@ Enabling starts configured plugins; disabling tears them down. Automation must i
 Use an absolute path on the daemon machine:
 
 ```bash
-paseo plugin init /absolute/path/to/counter-plugin
-cd /absolute/path/to/counter-plugin
+paseo plugin init /absolute/path/to/workspace-plugin
+cd /absolute/path/to/workspace-plugin
 npm install
 ```
 
@@ -37,51 +37,54 @@ npm install
 Replace `index.tsx` with:
 
 ```tsx
-import type { PluginContext } from "@paseo/plugin";
-import React, { useState } from "react";
-import { Pressable, Text, View } from "react-native";
-
-function Counter() {
-  const [count, setCount] = useState(0);
+import { type PluginContext, type PluginWorkspacePanelProps, useWorkspace } from "@paseo/plugin";
+import { Text, View } from "react-native";
 
+function WorkspaceOverview({ workspaceId }: PluginWorkspacePanelProps) {
+  const workspace = useWorkspace(workspaceId, ({ name, directory }) => ({
+    name,
+    directory,
+  }));
   return (
-    <View style={{ flex: 1, padding: 24, gap: 16 }}>
-      <Text style={{ fontSize: 48 }}>{count}</Text>
-      <Pressable
-        accessibilityRole="button"
-        accessibilityLabel={`Increment counter, currently ${count}`}
-        onPress={() => setCount((value) => value + 1)}
-        style={{ padding: 16, borderRadius: 12, backgroundColor: "#238253" }}
-      >
-        <Text style={{ color: "white", textAlign: "center" }}>Count me in</Text>
-      </Pressable>
+    <View style={{ flex: 1, padding: 24, gap: 8 }}>
+      <Text style={{ fontSize: 24 }}>{workspace?.name}</Text>
+      <Text>{workspace?.directory}</Text>
     </View>
   );
 }
 
 export default function contribute(plugin: PluginContext) {
-  plugin.addSurface("main", Counter);
-  plugin.addSidebarItem({
-    id: "main",
-    title: "Counter",
-    icon: "ListPlus",
-    surface: "main",
+  plugin.addWorkspacePanel({
+    id: "overview",
+    title: "Workspace overview",
+    icon: "PanelsTopLeft",
+    context: "workspace",
+    Component: WorkspaceOverview,
   });
-  return () => undefined;
+  plugin.addCommandCenterItem({
+    id: "open-overview",
+    title: "Open workspace overview",
+    icon: "PanelsTopLeft",
+    context: "workspace",
+    onSelect({ openPanel }) {
+      openPanel("overview");
+    },
+  });
+  return () => {};
 }
 ```
 
-The icon is a [Lucide](https://lucide.dev/icons/) icon name. The surface uses React Native primitives, so the same contribution works in the desktop, browser, iOS, and Android clients.
+The icon is a [Lucide](https://lucide.dev/icons/) icon name. The panel uses React Native primitives, so the same contribution works in the desktop, browser, iOS, and Android clients. Panel props contain stable IDs; `useWorkspace` selects the cached fields the component needs without fetching through RPC or re-rendering for unrelated workspace changes.
 
 ## Check and install it
 
 ```bash
 npm run typecheck
-paseo plugin install /absolute/path/to/counter-plugin
+paseo plugin install /absolute/path/to/workspace-plugin
 paseo plugin ls
 ```
 
-Open **Counter** in the Paseo sidebar. If the item does not appear, confirm that **Enable plugins** is on, the plugin status is `running` in `paseo plugin ls`, and the client is viewing the host where you installed it.
+Open a workspace, open the Command Center, and choose **Open workspace overview**. It opens as a normal workspace tab. If the item does not appear, confirm that **Enable plugins** is on, the plugin status is `running` in `paseo plugin ls`, and the client is viewing the host where you installed it.
 
 ## Edit and reload
 
@@ -89,7 +92,7 @@ Source changes are explicit:
 
 ```bash
 npm run typecheck
-paseo plugin reload counter-plugin
+paseo plugin reload workspace-plugin
 ```
 
 A reload stops the old plugin, runs its cleanup, compiles the current source, and starts it again. A failed reload stays failed and reports its load error; fix the source and reload again.
@@ -106,8 +109,8 @@ console.error("Issue refresh failed", error);
 Read recent stdout and stderr from **Settings → Plugins → Logs** or the CLI:
 
 ```bash
-paseo plugin logs counter-plugin
-paseo plugin logs counter-plugin --json
+paseo plugin logs workspace-plugin
+paseo plugin logs workspace-plugin --json
 ```
 
 The log tail survives reloads and crashes, so inspect it when a plugin fails to start or an RPC