feat(orchestrator): S3 generated SVG faces whose mouths move while speaking

Requirement 001 phase 6, S3:

- faces.js derives a face from the agent's stable key (its session id,
  or name:<name> without a session), so a rename keeps the face: shape
  4, colour 7, eyes 5, brows 4, mouth 5, hair or headwear 6, accessory 5,
  84,000 combinations. It emits constant SVG tags and attributes only.
- The emoji avatar is gone: popup, Orbit and Chord nodes, the radio
  view, stream and palette draw the SVG face (the 3D views keep their
  marker).
- While the radio reads an agent's message, its faces carry the class
  speaking and the mouth runs the talk keyframes; a silent face does
  not move, and prefers-reduced-motion stops the mouth.

Evidence: make test 673 OK, ruff and markdownlint clean
(/tmp/s3-make-test-1.log); e2e 20 OK in Chromium and Firefox, none
skipped (/tmp/s3-e2e-3.log); screenshots
/tmp/orchestrator-phase4-shots/*-speaking.png; MEDUSA 13 files, 2
findings ("PLA" in "templates", the UI call openAgent) accepted after
an independent skeptic that found no markup sink or selector injection
in the face code.

🎯 Fix: 94 %
💥 Break: 3 %
💸 Cost: 100 %
⏱️ Time: –
🛡️ Security: 100 %
🏆 Score: 91
🚦 Gate: ✅ 90/5, cost and time <= 100, security 100 %

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/requirements/001-agent-orchestrator.md

@@ -603,9 +603,9 @@ flowchart TD
 
 ### Phase 6: faces (S3)
 
-- [ ] The face generator yields at least 1000 distinct attribute
+- [x] The face generator yields at least 1000 distinct attribute
       combinations and the same face for the same agent id (unit test).
-- [ ] A speaking agent's face animates its mouth; a silent one does not
+- [x] A speaking agent's face animates its mouth; a silent one does not
       (DOM test on the class while the radio plays).
 
 ### Phase 6: night commands (S4)