FRE-605: Implement Phase 4 Change Tracking & Merge Logic

- Create ChangeTracker class with full version history support
  - Document change recording with metadata
  - Snapshot creation and restoration
  - Change acceptance/rejection workflow
  - Change diff generation between snapshots
  - Event-based change notifications

- Implement MergeLogic with screenplay-specific rules
  - Server change application with conflict detection
  - Auto-resolution for non-overlapping edits
  - Scene-aware merge rules (same-scene vs different-scene)
  - Manual conflict resolution workflow
  - Merge validation

- Write comprehensive unit tests
  - Change recording and tracking tests
  - Snapshot management tests
  - Conflict resolution tests
  - Screenplay-specific merge rule tests

- Document implementation in analysis/fre605_change_tracking_implementation.md

Architecture: ChangeTracker integrates with Yjs document updates.
MergeLogic applies screenplay-specific rules for concurrent edits.

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

src/lib/analytics/index.ts

@@ -0,0 +1,5 @@
+export * from "./kpi-service";
+export * from "./slack-alerts";
+export * from "./report-generator";
+export * from "./cohort-analysis";
+export * from "./nps-service";