feat(human-flow): AST-based scanner v2 + Friction Index rubric

Upgrade the human-flow skill (Gemini-assisted, Claude-reviewed):
- scan.mjs rewritten to AST-based (@babel/parser/traverse) with 4
  detectors: unlabeled-icon-button, tiny-target, missing-feedback-props,
  click-without-keyboard; regex fallback on parse failure.
- Objective Friction Index (Motor 3.0 / Cognitive 2.5 / Keyboard 2.5 /
  Feedback 2.0); 0-10 Human Workflow Score.
- New heuristics: State-Flow Audit, Precision Rail / Fumble Zones,
  Restraint-o-Meter (1-5) for the fancy pass.
- `fix` command DISABLED for now (advisory only): the AST generator
  reprints whole files and produces noisy diffs; agents apply surgical
  fixes from the report. To be revisited with a string-splice editor.
- Add @babel/* deps + package-lock.json.
- Memory: agy review/review-files is NOT actually read-only (wrote files
  + ran npm despite documented plan-mode) — diff after every agy review.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.claude/skills/human-flow/references/report-template.md

@@ -7,12 +7,14 @@ Use this structure for all `scan`, `audit`, and `report` outputs.
 ## Human-Flow Report: <Target / Component / Page>
 
 **Date**: YYYY-MM-DD  
-**Scanner**: human-flow v1 (mouse + keyboard intuition focus)  
-**Scope**: <files/components scanned>  
-**Overall Human Workflow Score**: X/10  
-- Mouse Ergonomics: X/10  
-- Keyboard Parity & Efficiency: X/10  
-- Workflow Discoverability & Friction: X/10  
+**Scanner**: human-flow v2 (AST-Powered)  
+**Overall Human Workflow Score**: X/10
+
+### Friction Index Rubric
+- **Motor (3.0)**: Target size, precision, travel distance.
+- **Cognitive (2.5)**: Discoverability, affordance, consistency.
+- **Keyboard (2.5)**: Accessibility, focus flow, parity.
+- **Feedback (2.0)**: Visual response, state transitions.
 
 **Summary**  
 (2-4 sentences: the biggest sources of unintuitive behavior for a human operator using mouse and keyboard, and the net effect on daily workflow.)