feat(sprint18): editor autosave/reset, admin auth, QR reuse, Ed25519 prep

- Project editor: persist draft to localStorage, restore on reload,
  last-saved/draft-restored status indicators, section/whole-draft reset
  with confirmation.
- Extract shared QR/polling/expiry engine from TelegramLoginComponent
  (shared/qr-login) and reuse it for a new admin login flow.
- Admin authentication kept fully separate from customer session:
  own cookie/localStorage keys, signals, guard, and header interceptor
  (core/admin-auth).
- ?login=true / ?adminLogin=true open the respective login dialog for
  manual testing.
- Ed25519 challenge/verify interfaces (fail-closed no-op binding) ready
  for backend delivery.
- Document autosave/reset/admin-auth/QR-reuse/Ed25519 model and the
  remaining full-field-coverage gap in docs/Project-Editor.md.

src/app/features/project-editor/facade/project-editor.facade.ts

@@ -9,6 +9,8 @@ import { LocaleSyncService } from '../services/locale-sync.service';
 import { ProjectEditorState } from '../models/project-editor.model';
 import { PlatformRuntimeService } from '../../../core/runtime/platform-runtime.service';
 import { ProjectValidator } from '../services/project-validator.service';
+import { ProjectEditorDraftStorageService } from '../services/project-editor-draft-storage.service';
+import { EDITOR_SECTION_BOOTSTRAP_KEYS } from '../models/project-editor.model';
 
 @Injectable({ providedIn: 'root' })
 export class ProjectEditorFacade {
@@ -18,13 +20,17 @@ export class ProjectEditorFacade {
   private readonly localeSync = inject(LocaleSyncService);
   private readonly runtime = inject(PlatformRuntimeService);
   private readonly validator = inject(ProjectValidator);
+  private readonly draftStorage = inject(ProjectEditorDraftStorageService);
 
   private readonly state = signal<ProjectEditorState>({
     bootstrap: null,
+    originalBootstrap: null,
     importError: null,
     activeSection: 'general',
     status: 'draft',
     lastSavedBootstrap: null,
+    lastSavedAt: null,
+    draftRestored: false,
   });
 
   readonly bootstrap = computed(() => this.state().bootstrap);
@@ -33,6 +39,8 @@ export class ProjectEditorFacade {
   readonly homepagePage = computed(() => this.bootstrap()?.pages.find(page => page.key === 'home' || page.route.path === '/') ?? null);
   readonly homepageWidgets = computed(() => this.homepagePage()?.sections.flatMap(section => section.widgets.map(widget => ({ sectionId: section.id, sectionType: section.type, widget }))) ?? []);
   readonly status = computed(() => this.state().status);
+  readonly lastSavedAt = computed(() => this.state().lastSavedAt);
+  readonly draftRestored = computed(() => this.state().draftRestored);
   readonly validationIssues = computed(() => {
     const current = this.bootstrap();
     return current ? this.validator.validate(current) : [];
@@ -49,7 +57,19 @@ export class ProjectEditorFacade {
     this.configService.loadBootstrap(true).pipe(take(1)).subscribe({
       next: config => {
         const normalized = this.normalize(JSON.parse(JSON.stringify(config)) as BootstrapConfig);
-        this.state.update(current => ({ ...current, bootstrap: normalized, importError: null, lastSavedBootstrap: normalized, status: 'draft' }));
+        const storedDraft = this.draftStorage.load(normalized.tenant.id);
+        const restoredFromDraft = storedDraft !== null;
+        const bootstrap = restoredFromDraft ? this.normalize(storedDraft!.bootstrap) : normalized;
+        this.state.update(current => ({
+          ...current,
+          bootstrap,
+          originalBootstrap: normalized,
+          importError: null,
+          lastSavedBootstrap: normalized,
+          lastSavedAt: restoredFromDraft ? storedDraft!.savedAt : null,
+          status: 'draft',
+          draftRestored: restoredFromDraft,
+        }));
       },
       error: () => this.state.update(current => ({ ...current, bootstrap: null, importError: 'builder.importError' })),
     });
@@ -61,10 +81,13 @@ export class ProjectEditorFacade {
       return;
     }
 
-    this.state.update(state => ({
-      ...state,
-      bootstrap: this.normalize(updater(JSON.parse(JSON.stringify(current)) as BootstrapConfig)),
-    }));
+    const next = this.normalize(updater(JSON.parse(JSON.stringify(current)) as BootstrapConfig));
+    this.state.update(state => ({ ...state, bootstrap: next, draftRestored: false }));
+    this.draftStorage.save(next);
+  }
+
+  dismissDraftRestoredNotice(): void {
+    this.state.update(current => ({ ...current, draftRestored: false }));
   }
 
   exportBootstrap(): string {
@@ -115,7 +138,35 @@ export class ProjectEditorFacade {
     if (!current) {
       return;
     }
-    this.state.update(state => ({ ...state, lastSavedBootstrap: JSON.parse(JSON.stringify(current)) }));
+    const savedAt = this.draftStorage.save(current);
+    this.state.update(state => ({ ...state, lastSavedBootstrap: JSON.parse(JSON.stringify(current)), lastSavedAt: savedAt }));
+  }
+
+  /** Reverts one section's bootstrap keys to the originally loaded/published snapshot. Caller is responsible for confirmation UX. */
+  resetSection(sectionId: ProjectEditorState['activeSection']): void {
+    const original = this.state().originalBootstrap;
+    const keys = EDITOR_SECTION_BOOTSTRAP_KEYS[sectionId];
+    if (!original || !keys) {
+      return;
+    }
+    this.updateBootstrap(current => {
+      const patch: Partial<BootstrapConfig> = {};
+      for (const key of keys) {
+        (patch as Record<string, unknown>)[key] = JSON.parse(JSON.stringify(original[key]));
+      }
+      return { ...current, ...patch };
+    });
+  }
+
+  /** Discards the entire draft, reverting to the originally loaded/published bootstrap. Caller is responsible for confirmation UX. */
+  resetDraft(): void {
+    const original = this.state().originalBootstrap;
+    if (!original) {
+      return;
+    }
+    const reset = this.normalize(JSON.parse(JSON.stringify(original)) as BootstrapConfig);
+    this.draftStorage.clear();
+    this.state.update(state => ({ ...state, bootstrap: reset, lastSavedAt: null, draftRestored: false }));
   }
 
   publish(): boolean {
@@ -124,10 +175,13 @@ export class ProjectEditorFacade {
       return false;
     }
     this.runtime.reloadFromBootstrap(current);
+    const savedAt = this.draftStorage.save(current);
     this.state.update(state => ({
       ...state,
       status: 'published',
       lastSavedBootstrap: JSON.parse(JSON.stringify(current)),
+      originalBootstrap: JSON.parse(JSON.stringify(current)),
+      lastSavedAt: savedAt,
     }));
     return true;
   }