docs: update SESSION_STATE.md with cleanup session summary

dev_docs/SESSION_STATE.md

@@ -1,9 +1,51 @@
 # CURRENT AI WORKING SESSION — HANDOVER
 
 **Active AI:** Claude Haiku 4.5
-**Last Updated:** 2026-04-19 (Session 9 - Zoom Button Debug)
+**Last Updated:** 2026-04-19 (Session 10 - Project Cleanup)
 **Current Version:** v1.10.16 (version saved and merged to master)
-**Branch:** refactor/ai-friendly-v2 (All 3 Phases: ✅ FINAL VALIDATION COMPLETE)
+**Branch:** cleanup/remove-old-artifacts (Merged to dev with tag "project cleaned")
+
+---
+
+## WHAT WAS COMPLETED THIS SESSION (Session 10: Project Cleanup)
+
+### Project Cleanup — COMPLETE ✅
+
+**Objective:** Remove implemented plans, completed reports, debug guides, and old release artifacts to clean up the repository.
+
+**Files Deleted (11 total):**
+
+**Implemented Plans & Archives:**
+- `dev_docs/BOX_SCANNING_MASTER_PLAN.md` — Completed master plan
+- `dev_docs/SECURITY_AUDIT_PLAN.md` — Completed security audit plan
+- `dev_docs/SECURITY_REPORT.md` — Completed security report
+- `dev_docs/PLAN_HISTORY.md` — Historical plan archive
+- `dev_docs/SESSION_HISTORY.md` — Historical session archive
+
+**Completed Reports:**
+- `PHASE_2_COMPLETION_REPORT.md` — Phase 2 completion documentation
+- `REFACTORING_PROGRESS.md` — Refactoring progress tracker
+- `REFACTORING_COMPLETE.md` — Refactoring completion marker
+- `PLAN.md` — Old master plan file
+
+**Debug & Temporary Files:**
+- `ZOOM_DEBUG_GUIDE.md` — Debug guide (debugging complete)
+- `.impeccable.md` — Temporary style file
+
+**Files Preserved (Core Artifacts):**
+- ✅ CLAUDE.md — Project instructions
+- ✅ AI_RULES.md — Operational constraints
+- ✅ PROJECT_ARCHITECTURE.md — System architecture
+- ✅ README.md — Project overview
+- ✅ dev_docs/SESSION_STATE.md — Current session state (this file)
+- ✅ dev_docs/ARCHIVE_LOGS.md — Historical context
+- ✅ config/ai_prompt.md — Configuration
+
+**Branch Created:** `cleanup/remove-old-artifacts`
+**Commit:** `4366c772` chore: remove old plans, reports, and debug artifacts
+**Impact:** 1272 lines removed, 11 files deleted, zero files modified
+
+**Status:** Cleanup complete and merged to dev with tag "project cleaned"
 
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