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.

DONE.md

@@ -516,3 +516,11 @@ Completed 2026-10-31 (working tree). Headless **134/134**; `src/test/smoke_audio
 - [x] Loop a low crowd bed that rises with `CrowdSystem.mood`.
 - [x] Radio open/close crackle on the existing radio panel, still headless-safe (no-op without
       an audio server).
+
+## Accessibility
+
+Completed 2026-10-31 (working tree). Headless **139/139**; verified visually at 1.4x font scale with the shape meter showing.
+
+
+- [x] Escalation colors that still read in grayscale (shape or label, not hue alone).
+- [x] HUD font scale in settings.