initial: dungeon crawler with Bun + TypeScript modular architecture

- 19 TypeScript modules under src/ (constants, entities, room, game, render)
- Canvas 2D rendering with dark fantasy palette
- Room-based navigation, random 7x7 map generation
- Two combat modes: ranged (pistol) and melee (knife)
- Wall collision with door opening support
- Minimap, HP bar, enemy AI
- Bun build pipeline: src/main.ts -> dist/main.js + dist/index.html

src/types.ts

@@ -0,0 +1,17 @@
+export type RoomType = 'spawn' | 'normal' | 'treasure' | 'boss';
+export type Dir = 'up' | 'down' | 'left' | 'right';
+export type CombatMode = 0 | 1; // MODE_RANGED | MODE_MELEE
+
+export interface Box {
+  x: number;
+  y: number;
+  w: number;
+  h: number;
+}
+
+export interface Doors {
+  up: boolean;
+  down: boolean;
+  left: boolean;
+  right: boolean;
+}