feat(launcher): implement Phase 5 system management UI and relay

- Expose new native handlers in electron_relay.ts (Wallpaper, Updates, Window Control, Power).
- Overhaul Native OS Management UI with controls for window states, display layouts, and power.
- Add Application Updates component with support for local and web sources.
- Include confirmation modal for dangerous system actions (shutdown/reboot).
- Update TODO.md to mark Phase 5 integration as completed.

src/lib/electron/electron_relay.ts

@@ -183,6 +183,43 @@ export async function control_presentation({
     return { success: false, error: `Unsupported app or action: ${app}/${action}` };
 }
 
+// 4. System Management (Phase 5+)
+
+export async function set_wallpaper({ path }: { path: string }) {
+    if (!native || !native.set_wallpaper) return { success: false, error: 'Native handler set_wallpaper not available' };
+    return await native.set_wallpaper({ path });
+}
+
+export async function update_app(args: { source: 'url' | 'file', url?: string, path?: string }) {
+    if (!native || !native.update_app) return { success: false, error: 'Native handler update_app not available' };
+    return await native.update_app(args);
+}
+
+export async function window_control({ action, value }: { action: string, value?: any }) {
+    if (!native || !native.window_control) return { success: false, error: 'Native handler window_control not available' };
+    return await native.window_control({ action, value });
+}
+
+export async function manage_recording({ action, options }: { action: 'start' | 'stop' | 'status', options?: any }) {
+    if (!native || !native.manage_recording) return { success: false, error: 'Native handler manage_recording not available' };
+    return await native.manage_recording({ action, options });
+}
+
+export async function set_display_layout({ mode, configStr }: { mode: 'mirror' | 'extend', configStr?: string }) {
+    if (!native || !native.set_display_layout) return { success: false, error: 'Native handler set_display_layout not available' };
+    return await native.set_display_layout({ mode, configStr });
+}
+
+export async function power_control({ action }: { action: 'shutdown' | 'reboot' | 'sleep' }) {
+    if (!native || !native.power_control) return { success: false, error: 'Native handler power_control not available' };
+    return await native.power_control({ action });
+}
+
+export async function open_external({ url, app }: { url: string, app?: 'chrome' | 'firefox' | 'default' }) {
+    if (!native || !native.open_external) return { success: false, error: 'Native handler open_external not available' };
+    return await native.open_external({ url, app });
+}
+
 /**
  * List Tools (Self-Documentation)
  * Returns a JSON manifest of all available native bridge functions.