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.

project.godot

@@ -8,7 +8,7 @@ config_version=5
 
 config/name="Step Line"
 config/description="Workplace security simulation about observation, access verification, and proportionate escalation."
-config/version="0.2.8"
+config/version="0.2.9"
 run/main_scene="res://scenes/main.tscn"
 config/features=PackedStringArray("4.3", "GL Compatibility")