FRE-594: Implement revision tracking and version history system

Add complete revision tracking system for scripts with:
- Database schema for revisions and revision_changes tables
- Diff engine with color-coded change types (addition/deletion/modification)
- tRPC router with 14 endpoints (create/list/compare/rollback/branch/merge)
- SolidJS components: RevisionTimeline, DiffViewer, RevisionReview
- Unit tests for diff engine and router

Co-Authored-By: Paperclip <noreply@paperclip.ing>

src/lib/revisions/index.ts

@@ -0,0 +1,2 @@
+export * from './types';
+export * from './diff';