Move ~4,100 lines of accessibility code from diablo.cpp into 6 new
modules, reducing diablo.cpp from ~7,700 to ~3,660 lines.
New modules:
- controls/accessibility_keys: UI key handlers and guard functions
(IsPlayerDead, IsGameRunning, CanPlayerTakeAction, etc.)
- utils/walk_path_speech: BFS pathfinding, PosOk variants, walk
direction helpers, and path-to-speech formatting
- utils/accessibility_announcements: periodic announcements for low
HP warning sound, durability, boss health, monsters, doors
- controls/town_npc_nav: town NPC selection cycling and auto-walk
- utils/navigation_speech: exit/stairs/portal/unexplored speech and
keyboard walk key handlers
- controls/tracker: target category cycling, candidate finding,
pathfinding navigation, and auto-walk tracker
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>