feat(plugins): resizable collapsible detail sidebar, auto-init on refresh

- Add email-detail-sidebar slot type for right-side plugin panels
- Plugin sidebar inside EmailViewer with ResizeHandle (200-500px, drag/dbl-click reset)
- Collapse/expand toggle with PanelRightClose/PanelRightOpen icons
- Call initializePlugins() on mount so plugins survive page refresh
- Fix plugin loader: call exposePluginExternals() before loading
- Fix CSP: add blob: to script-src for plugin bundle loading
- Fix enablePlugin: wire slot registration bridge before loading
- Fix email-banner PluginSlot: pass email via extraProps
- Fix sidebar-widget PluginSlot: move inside scrollable area
- Emit emailHooks.onEmailOpen/onEmailClose from selectEmail()

stores/plugin-store.ts

@@ -19,7 +19,7 @@ import { removeAllPluginHooks } from '@/lib/plugin-hooks';
 
 const SLOT_NAMES: SlotName[] = [
   'toolbar-actions', 'email-banner', 'email-footer', 'composer-toolbar',
-  'sidebar-widget', 'settings-section', 'context-menu-email', 'navigation-rail-bottom',
+  'sidebar-widget', 'email-detail-sidebar', 'settings-section', 'context-menu-email', 'navigation-rail-bottom',
 ];
 
 function emptySlots(): Record<SlotName, SlotRegistration[]> {
@@ -136,6 +136,10 @@ export const usePluginStore = create<PluginStoreState>()(
         const plugin = plugins.find(p => p.id === id);
         if (!plugin) return;
 
+        // Ensure bridges are wired before loading (may not have run initializePlugins yet)
+        setPluginStoreAccessor({ setPluginStatus: get().setPluginStatus });
+        setSlotRegistrationBridge(get().registerSlot);
+
         set({
           plugins: plugins.map(p =>
             p.id === id ? { ...p, enabled: true, status: 'enabled' as PluginStatus, error: undefined } : p