feat: Brainstorm Topics with GSC + Issue #518 fixes + Blog Editor enhancements

Issue #518 - Subscription not updating after checkout:
- Fix stale closure in SubscriptionContext checkout polling (use subscriptionRef)
- Move checkout success polling from InitialRouteHandler into SubscriptionContext
- Remove redundant polling code from InitialRouteHandler
- Fix plan label: 'Free' instead of 'No Plan', proper capitalization
- Add plan refresh button in UserBadge
- Add 'View Costing Details' to UserBadge dropdown
- Rename 'ALwrity Podcast Maker' to 'Podcast Creator' across UI
- Clean subscription=success URL param after verification

Blog Writer WYSIWYG Editor enhancements:
- Per-section preview toggle (view/edit icons)
- Enhanced hover-based toolbar
- Circular SVG progress stats bar with detailed tooltip
- Research tool chips in stats bar footer
- Per-section TTS with useTextToSpeech hook (browser native)
- Full blog preview modal with print/PDF support
- PlayAllTTSButton: sequential playback with progress bar
- OnThisPageNav: floating sidebar with scroll tracking
- Section data attributes for scroll anchoring

GSC Brainstorm Topics feature:
- Backend: gsc_brainstorm_service.py (rule-based + LLM recommendations)
- Backend: POST /gsc/brainstorm endpoint with 3-word minimum validation
- Frontend: gscBrainstorm.ts API client
- Frontend: useGSCBrainstormConnection hook (popup OAuth, no /onboarding redirect)
- Frontend: useGSCBrainstorm hook (connect check + brainstorm call)
- Frontend: GSCBrainstormModal (3-tab results: Opportunities, Gaps, AI Recs)
- Frontend: BrainstormButton (visible at 3+ words, GSC connect overlay)
- Wire BrainstormButton into ManualResearchForm and ResearchAction
- Add blog_writer to gsc_auth router features for ALWRITY_ENABLED_FEATURES

backend/alwrity_utils/router_manager.py

@@ -44,8 +44,8 @@ CORE_ROUTER_REGISTRY = [
 OPTIONAL_ROUTER_REGISTRY = [
     {"name": "blog_writer", "module": "api.blog_writer.router", "attr": "router", "features": {"all", "blog_writer"}},
     {"name": "story_writer", "module": "api.story_writer.router", "attr": "router", "features": {"all", "story_writer"}},
-    {"name": "wix", "module": "api.wix_routes", "attr": "router", "features": {"all"}},
-{"name": "wix_test", "module": "api.wix_routes", "attr": "qa_router", "features": {"all"}},
+{"name": "wix", "module": "api.wix_routes", "attr": "router", "features": {"all"}},
+    {"name": "wix_test", "module": "api.wix_routes", "attr": "qa_router", "features": {"all"}},
     {"name": "blog_seo_analysis", "module": "api.blog_writer.seo_analysis", "attr": "router", "features": {"all", "blog_writer"}},
     {"name": "persona", "module": "api.persona_routes", "attr": "router", "features": {"all", "persona"}},
     {"name": "video_studio", "module": "api.video_studio.router", "attr": "router", "features": {"all", "video_studio"}},