Add accessibility pass: escalation meter and working HUD font scale

- Escalation cue now includes a shape meter and numeric level
  ("Escalation: Blocking [###--] L3/5") in addition to the colour and name, so it
  reads in grayscale. Hud.escalation_meter(level) is pure and tested.
- HUD font scale from settings actually works: set_font_scale() resizes fonts via
  theme overrides instead of Control.scale, which pushed the right-anchored clock
  label off-screen. It now covers the top, log, target, hint, time, mode,
  escalation, cooldown, and debug labels.
- Settings load before the HUD exists, so _ready() re-applies player settings after
  _build_ui(); previously a saved font scale was ignored until the next apply.

Tests/docs
- Headless suite 134 -> 139 (test_accessibility.gd).
- Verified visually at 1.4x scale: no overflow, meter readable.
- README, TODO section moved to DONE, MEMORY. Version 0.2.9.

TODO.md

@@ -1,15 +1,10 @@
 # TODO
 
-Godot 4.3 prototype. Release **v0.2.8** is tagged. Headless suite **134/134**, plus the session,
+Godot 4.3 prototype. Release **v0.2.9** is tagged. Headless suite **139/139**, plus the session,
 PLAN-verb, crowd, emergency, timeline, audio, and windowed focus/radial smokes.
 
 Host `REQUIRE_SIGNIN_VIEW` stays deferred.
 
-## Accessibility
-
-- [ ] Escalation colors that still read in grayscale (shape or label, not hue alone).
-- [ ] HUD font scale in settings.
-
 ## Scenario content still missing vs PLAN lists
 
 - [ ] Joke Shop: guest on the reservation list without ID; borrowed/mismatched ID; guest