v1.0.0: ship-ready polish sprint

- Dark mode consistency audit + SVG favicon + OG meta tags
- Sentry error tracking (conditional, tree-shaken when no DSN)
- PostHog product analytics (7 key events tracked)
- Stripe billing integration (checkout + webhook edge functions)
- Version bump to 1.0.0

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

Author: 2 people

package.json

@@ -1,7 +1,7 @@
 {
   "name": "sourcekit",
   "private": true,
-  "version": "0.0.0",
+  "version": "1.0.0",
   "type": "module",
   "scripts": {
     "dev": "vite",