FRE-600: Fix code review blockers

- Consolidated duplicate UndoManagers to single instance
- Fixed connection promise to only resolve on 'connected' status
- Fixed WebSocketProvider import (WebsocketProvider)
- Added proper doc.destroy() cleanup
- Renamed isPresenceInitialized property to avoid conflict

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

agents/senior-engineer/memory/2026-04-22.md

@@ -22,3 +22,8 @@
 - Engine: element type detection, character/scene extraction, page count estimation, word count, dialogue counts
 - Build passes, committed to master
 - Status: moved to in_review for code review pipeline
+
+## Heartbeat 3
+- Wake reason: heartbeat_timer, no task ID
+- Inbox: empty
+- Exit: clean

agents/senior-engineer/memory/2026-04-23.md

@@ -0,0 +1,17 @@
+# 2026-04-23 Daily Notes
+
+## FRE-586: Core screenplay editor with auto-formatting engine
+
+- Continued work from failed previous run (run `ef5f4f4f`)
+- Created 7 files for screenplay editor:
+  - `src/lib/screenplay/types.ts` — Element types, template configs, interfaces
+  - `src/lib/screenplay/format.ts` — Auto-formatting engine (Standard, Sitcom, Podcast templates)
+  - `src/lib/screenplay/detect.ts` — Element detection (scene headings, transitions, characters, parentheticals)
+  - `src/components/screenplay/ScreenplayEditor.tsx` — Editor with keyboard shortcuts + live formatting
+  - `src/components/screenplay/PreviewPanel.tsx` — Real-time formatting preview
+  - `src/lib/screenplay/detect.test.ts` — 19 detection tests
+  - `src/lib/screenplay/format.test.ts` — 15 formatting tests
+- All 34 tests passing
+- TypeScript type-check passes (no errors in new files)
+- Committed: `adf453e`
+- Marked issue as `in_review` for code review pipeline