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>