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/BlogWriter.tsx

@@ -1,5 +1,5 @@
 import React, { useRef, useCallback, useState } from 'react';
-import { useNavigate } from 'react-router-dom';
+import { useNavigate, useSearchParams } from 'react-router-dom';
 import Dialog from '@mui/material/Dialog';
 import DialogTitle from '@mui/material/DialogTitle';
 import DialogContent from '@mui/material/DialogContent';
@@ -36,6 +36,8 @@ import { BlogWriterLandingSection } from './BlogWriterUtils/BlogWriterLandingSec
 import { CopilotKitComponents } from './BlogWriterUtils/CopilotKitComponents';
 
 const BlogWriter: React.FC = () => {
+  const [searchParams, setSearchParams] = useSearchParams();
+
   // Add light theme class to body/html on mount, remove on unmount
   React.useEffect(() => {
     document.body.classList.add('blog-writer-page');
@@ -76,6 +78,7 @@ const BlogWriter: React.FC = () => {
     flowAnalysisCompleted,
     flowAnalysisResults,
     sectionImages,
+    restoreAttempted,
     setResearch,
     setOutline,
     setTitleOptions,
@@ -203,6 +206,21 @@ const BlogWriter: React.FC = () => {
   // Store navigateToPhase in a ref for use in polling callbacks
   const navigateToPhaseRef = React.useRef<((phase: string) => void) | null>(null);
 
+  // Normalize section keys to match outline IDs when updating from API responses
+  const handleSectionsUpdate = useCallback((newSections: Record<string, string>) => {
+    if (outline && outline.length > 0 && Object.keys(newSections).length > 0) {
+      const normalized: Record<string, string> = {};
+      const values = Object.values(newSections);
+      outline.forEach((s, idx) => {
+        const id = String(s.id);
+        normalized[id] = newSections[id] ?? values[idx] ?? '';
+      });
+      setSections(normalized);
+    } else {
+      setSections(newSections);
+    }
+  }, [outline, setSections]);
+
   // Polling hooks - extracted to useBlogWriterPolling
   const {
     researchPolling,
@@ -216,7 +234,7 @@ const BlogWriter: React.FC = () => {
     onResearchComplete: handleResearchComplete,
     onOutlineComplete: handleOutlineComplete,
     onOutlineError: handleOutlineError,
-    onSectionsUpdate: setSections,
+    onSectionsUpdate: handleSectionsUpdate,
     onContentConfirmed: () => {
       debug.log('[BlogWriter] Content generation completed - auto-confirming content');
       setContentConfirmed(true);
@@ -328,6 +346,14 @@ const BlogWriter: React.FC = () => {
       setContentConfirmed, setOutlineConfirmed, setSelectedTitle, setTitleOptions,
       setCurrentPhase]);
 
+  // Handle ?new=true query param from "New Blog" button in Asset Library
+  React.useEffect(() => {
+    if (searchParams.get('new') === 'true') {
+      handleNewBlog();
+      setSearchParams({}, { replace: true });
+    }
+  }, [searchParams, handleNewBlog, setSearchParams]);
+
   const handleMyBlogs = useCallback(() => {
     navigate('/asset-library?source_module=blog_writer&asset_type=text');
   }, [navigate]);
@@ -532,6 +558,7 @@ const BlogWriter: React.FC = () => {
         currentPhase={currentPhase}
         navigateToPhase={navigateToPhase}
         onResearchComplete={handleResearchComplete}
+        restoreAttempted={restoreAttempted}
       />
 
       {research && (
@@ -572,6 +599,8 @@ const BlogWriter: React.FC = () => {
           setShowOutlineModal(true);
         }}
         onContentGenerationStart={handleMediumGenerationStarted}
+        buildFullMarkdown={buildFullMarkdown}
+        convertMarkdownToHTML={convertMarkdownToHTML}
       />
         </>
       )}