sync: SEO canonical URLs, curation improvements, batch scripts, stats fix

- Dynamic canonical URLs and alternates for all pages (SEO fix)
- Shared seo.ts utility for canonical path generation
- Improved duplicate detection: standalone > aggregator priority, forks/created_at tie-breakers
- browseReadyFilter now includes unique aggregator skills
- Stats aligned with browseReadyFilter (was showing 16k instead of 62k+)
- Re-review mechanism: content_hash changes trigger needs-re-review
- review_status field added to skills schema
- Batch security scan and quality score scripts
- Indexer Dockerfile updated for curation deps
- Removed roadmap from README

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

scripts/init-db.sql

@@ -51,6 +51,9 @@ CREATE TABLE IF NOT EXISTS skills (
     is_blocked BOOLEAN DEFAULT FALSE,  -- Blocked from re-indexing (owner requested removal)
     last_scanned TIMESTAMP WITH TIME ZONE,
 
+    -- Review pipeline
+    review_status TEXT DEFAULT 'unreviewed',  -- 'unreviewed', 'auto-scored', 'ai-reviewed', 'verified', 'needs-re-review'
+
     -- Content
     content_hash TEXT,
     raw_content TEXT,