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

frontend/src/components/BlogWriter/BlogWriterUtils/useSEOManager.ts

@@ -233,13 +233,18 @@ export const useSEOManager = ({
       try {
         const hash = await hashContent(`${title}\n${fullMarkdown}`);
         const cacheKey = getSeoCacheKey(hash, title);
+        console.log('[SEOManager] SEO cache lookup', { cacheKey, hashLength: hash.length, titleLength: title.length, markdownLength: fullMarkdown.length });
         const cached = window.localStorage.getItem(cacheKey);
         if (cached) {
           const parsed = JSON.parse(cached);
           if (parsed && typeof parsed.overall_score === 'number' && parsed.category_scores) {
-            debug.log('[SEOManager] Restored cached SEO analysis', { cacheKey, score: parsed.overall_score });
+            console.log('[SEOManager] Restored cached SEO analysis', { cacheKey, score: parsed.overall_score });
             setSeoAnalysis(parsed);
+          } else {
+            console.log('[SEOManager] Cached SEO data invalid', { hasScore: parsed && typeof parsed.overall_score === 'number' });
           }
+        } else {
+          console.log('[SEOManager] SEO cache miss', { cacheKey });
         }
       } catch (e) {
         debug.log('[SEOManager] Failed to restore cached SEO analysis', e);