feat: Pre-migration checkpoint - updated docs and utilities

Updates before optimization_engine migration:
- Updated migration plan to v2.1 with complete file inventory
- Added OP_07 disk optimization protocol
- Added SYS_16 self-aware turbo protocol
- Added study archiver and cleanup utilities
- Added ensemble surrogate module
- Updated NX solver and session manager
- Updated zernike HTML generator
- Added context engineering plan
- LAC session insights updates

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.claude/skills/01_CHEATSHEET.md

@@ -30,6 +30,7 @@ requires_skills:
 | See best results | OP_04 | `optuna-dashboard sqlite:///study.db` or dashboard |
 | Export neural training data | OP_05 | `python run_optimization.py --export-training` |
 | Fix an error | OP_06 | Read error log → follow diagnostic tree |
+| **Free disk space** | **OP_07** | `archive_study.bat cleanup <study> --execute` |
 | Add custom physics extractor | EXT_01 | Create in `optimization_engine/extractors/` |
 | Add lifecycle hook | EXT_02 | Create in `optimization_engine/plugins/` |
 | Generate physics insight | SYS_16 | `python -m optimization_engine.insights generate <study>` |
@@ -219,6 +220,48 @@ python -c "import optuna; s=optuna.load_study('my_study', 'sqlite:///3_results/s
 
 ---
 
+## Disk Space Management (OP_07)
+
+FEA studies consume massive disk space. After completion, clean up regenerable files:
+
+### Quick Commands
+
+```bash
+# Analyze disk usage
+archive_study.bat analyze studies\M1_Mirror
+
+# Cleanup completed study (dry run first!)
+archive_study.bat cleanup studies\M1_Mirror\m1_mirror_V12
+archive_study.bat cleanup studies\M1_Mirror\m1_mirror_V12 --execute
+
+# Archive to dalidou server
+archive_study.bat archive studies\M1_Mirror\m1_mirror_V12 --execute
+
+# List remote archives
+archive_study.bat list
+```
+
+### What Gets Deleted vs Kept
+
+| KEEP | DELETE |
+|------|--------|
+| `.op2` (Nastran results) | `.prt, .fem, .sim` (copies of master) |
+| `.json` (params/metadata) | `.dat` (solver input) |
+| `1_setup/` (master files) | `.f04, .f06, .log` (solver logs) |
+| `3_results/` (database) | `.afm, .diag, .bak` (temp files) |
+
+### Typical Savings
+
+| Stage | M1_Mirror Example |
+|-------|-------------------|
+| Full | 194 GB |
+| After cleanup | 114 GB (41% saved) |
+| Archived to server | 5 GB local (97% saved) |
+
+**Full details**: `docs/protocols/operations/OP_07_DISK_OPTIMIZATION.md`
+
+---
+
 ## LAC (Learning Atomizer Core) Commands
 
 ```bash