chore: Project cleanup and Canvas UX improvements (Phase 7-9)

## Cleanup (v0.5.0)
- Delete 102+ orphaned MCP session temp files
- Remove build artifacts (htmlcov, dist, __pycache__)
- Archive superseded plan docs (RALPH_LOOP V2/V3, CANVAS V3, etc.)
- Move debug/analysis scripts from tests/ to tools/analysis/
- Archive redundant NX journals to archive/nx_journals/
- Archive monolithic PROTOCOL.md to docs/archive/
- Update .gitignore with missing patterns
- Clean old study files (optimization_log_old.txt, run_optimization_old.py)

## Canvas UX (Phases 7-9)
- Phase 7: Resizable panels with localStorage persistence
  - Left sidebar: 200-400px, Right panel: 280-600px
  - New useResizablePanel hook and ResizeHandle component
- Phase 8: Enable all palette items
  - All 8 node types now draggable
  - Singleton logic for model/solver/algorithm/surrogate
- Phase 9: Solver configuration
  - Add SolverEngine type (nxnastran, mscnastran, python, etc.)
  - Add NastranSolutionType (SOL101-SOL200)
  - Engine/solution dropdowns in config panel
  - Python script path support

## Documentation
- Update CHANGELOG.md with recent versions
- Update docs/00_INDEX.md
- Create examples/README.md
- Add docs/plans/CANVAS_UX_IMPROVEMENTS.md

CLAUDE.md

@@ -55,6 +55,49 @@ If working directory is inside a study (`studies/*/`):
 - If no study context: Offer to create one or list available studies
 - After code changes: Update documentation proactively (SYS_12, cheatsheet)
 
+### Step 5: Use DevLoop for Multi-Step Development Tasks
+
+**CRITICAL: For any development task with 3+ steps, USE DEVLOOP instead of manual work.**
+
+DevLoop is the closed-loop development system that coordinates AI agents for autonomous development:
+
+```bash
+# Plan a task with Gemini
+python tools/devloop_cli.py plan "fix extractor exports"
+
+# Implement with Claude
+python tools/devloop_cli.py implement
+
+# Test filesystem/API
+python tools/devloop_cli.py test --study support_arm
+
+# Test dashboard UI with Playwright
+python tools/devloop_cli.py browser --level full
+
+# Analyze failures
+python tools/devloop_cli.py analyze
+
+# Full autonomous cycle
+python tools/devloop_cli.py start "add new stress extractor"
+```
+
+**When to use DevLoop:**
+- Fixing bugs that require multiple file changes
+- Adding new features or extractors
+- Debugging optimization failures
+- Testing dashboard UI changes
+- Any task that would take 3+ manual steps
+
+**Browser test levels:**
+- `quick` - Smoke test (1 test)
+- `home` - Home page verification (2 tests)
+- `full` - All UI tests (5+ tests)
+- `study` - Canvas/dashboard for specific study
+
+**DO NOT default to manual debugging** - use the automation we built!
+
+**Full documentation**: `docs/guides/DEVLOOP.md`
+
 ---
 
 ## Quick Start - Protocol Operating System