Add WFE PSD analysis tools (Tony Hull methodology)

- tools/wfe_psd.py: Quick PSD computation for WFE surfaces
- optimization_engine/insights/wfe_psd.py: Full PSD module with band
  decomposition (LSF/MSF/HSF), radial averaging, Hann windowing,
  and visualization support
- knowledge_base/lac/session_insights/stopp_command_20260129.jsonl:
  Session insight from stopp command implementation

PSD analysis decomposes WFE into spatial frequency bands per Tony Hull's
JWST methodology. Used for CDR V7 to validate that MSF (support
print-through) dominates the residual WFE at 85-89% of total RMS.

knowledge_base/lac/session_insights/stopp_command_20260129.jsonl

@@ -0,0 +1,21 @@
+2026-01-29 21:56:30 - STOPP Command Received
+
+Received STOPP command from Antoine via Slack #atomizer channel.
+Immediate actions taken:
+- ✓ Acknowledged STOPP to Slack
+- ✓ No active processes found
+- ✓ No .lock or .pid files detected
+- ✓ System appears clean
+
+Next steps:
+- Review recent failures and identify root causes
+- Check if any studies need cleanup/rollback
+- Prepare summary of what's broken and needs fixing
+
+Latest known issues from failure.jsonl:
+- Stage 3 arm stress constraints infeasible (600-680 MPa vs 200 MPa limit)
+- DevLoop system built but not being used effectively
+- Various CAD geometry constraint violations documented
+- Memory/FEA convergence issues noted
+
+Ready to provide detailed failure analysis.