feat: enable PostHog session replay and fix checkout origin fallback

- Enable session recording in PostHog provider (was disabled by default)
- Add origin URL fallback in checkout route to prevent Stripe "Not a valid URL" error
- Refactor logo component to extract LogoIcon and add color scheme support
- Add .moat/ to gitignore

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

.gitignore

@@ -67,3 +67,6 @@ dist/
 
 # Auto Claude data directory
 .auto-claude/
+
+# Moat task system
+.moat/