feat: Add opt-out setting for anonymous usage reporting (#743)

* refactor: align VS Code update checks with web runtime parity

- VS Code now uses file-based installId (shared with web server)
- Accepts platform/arch from webview for consistent behavior
- Usage data collection now matches web implementation

* feat: Add opt-out setting for anonymous usage reporting in Appearance

- Add privacy control in Appearance settings to opt-out of anonymous usage reports
- Usage data includes only app version, platform, and runtime - no personal data or code collected
- Setting persists across all runtimes and controls the reportUsage parameter in update checks

packages/ui/src/lib/desktop.ts

@@ -144,6 +144,8 @@ export type DesktopSettings = {
 
   // User-added skills catalogs (persisted to ~/.config/openchamber/settings.json)
   skillCatalogs?: SkillCatalogConfig[];
+  // Opt-in to send anonymous usage reports for update checks (default: true)
+  reportUsage?: boolean;
 };
 
 type TauriGlobal = {

packages/ui/src/lib/persistence.ts

@@ -393,6 +393,9 @@ const applyDesktopUiPreferences = (settings: DesktopSettings) => {
   if (typeof settings.stickyUserHeader === 'boolean' && settings.stickyUserHeader !== store.stickyUserHeader) {
     store.setStickyUserHeader(settings.stickyUserHeader);
   }
+  if (typeof settings.reportUsage === 'boolean' && settings.reportUsage !== store.reportUsage) {
+    store.setReportUsage(settings.reportUsage);
+  }
   if (typeof settings.fontSize === 'number' && Number.isFinite(settings.fontSize) && settings.fontSize !== store.fontSize) {
     store.setFontSize(settings.fontSize);
   }
@@ -840,6 +843,10 @@ const sanitizeWebSettings = (payload: unknown): DesktopSettings | null => {
     result.skillCatalogs = skillCatalogs;
   }
 
+  if (typeof candidate.reportUsage === 'boolean') {
+    result.reportUsage = candidate.reportUsage;
+  }
+
   return result;
 };