Phase 0: Project setup for agent-driven development

- Phaser 3 + bitECS 0.4 + TypeScript + Vite stack
- BootScene with title screen
- 6 cursor rules (project context, agent workflow, ECS, chemistry, Phaser, data)
- Vitest configured with happy-dom
- GDD, engine analysis, implementation plan, progress tracking

Co-authored-by: Cursor <cursoragent@cursor.com>

.cursor/rules/ecs-patterns.mdc

@@ -0,0 +1,65 @@
+---
+description: bitECS 0.4 component and system conventions
+globs: src/ecs/**/*.ts
+alwaysApply: false
+---
+
+# ECS Patterns (bitECS 0.4)
+
+## Components — Plain Objects with Arrays
+```typescript
+// ✅ GOOD: plain object with number arrays
+export const Position = { x: [] as number[], y: [] as number[] };
+export const Health = { current: [] as number[], max: [] as number[] };
+
+// ❌ BAD: old API (defineComponent, Types) — removed in 0.4
+```
+
+## Entity Lifecycle
+```typescript
+import { createWorld, addEntity, addComponent, removeEntity } from 'bitecs';
+
+const world = createWorld();
+const eid = addEntity(world);
+addComponent(world, eid, Position);
+Position.x[eid] = 100;
+Position.y[eid] = 200;
+```
+
+## Queries — Direct Function Calls
+```typescript
+import { query, Not } from 'bitecs';
+
+// ✅ 0.4 API: query(world, components)
+const entities = query(world, [Position, Velocity]);
+for (const eid of entities) {
+  Position.x[eid] += Velocity.x[eid] * delta;
+}
+
+// Operators: Not, And, Or, Any, None
+const stationary = query(world, [Position, Not(Velocity)]);
+```
+
+## Observers (replace enterQuery/exitQuery)
+```typescript
+import { observe, onAdd, onRemove } from 'bitecs';
+
+observe(world, onAdd(Position), (eid) => { /* entity gained Position */ });
+observe(world, onRemove(Position), (eid) => { /* entity lost Position */ });
+```
+
+## Systems — Pure Functions
+```typescript
+export const movementSystem = (world: World, delta: number) => {
+  for (const eid of query(world, [Position, Velocity])) {
+    Position.x[eid] += Velocity.x[eid] * delta;
+    Position.y[eid] += Velocity.y[eid] * delta;
+  }
+};
+```
+
+## Rules
+- Components = plain objects with `[] as number[]` fields
+- Never store strings in components — use numeric IDs, look up in registry
+- Systems must not create Phaser objects — only the sync bridge does that
+- Parameter order: `addComponent(world, eid, component)` (world first, then eid)