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/data-files.mdc

@@ -0,0 +1,36 @@
+---
+description: Game data JSON schema and validation conventions
+globs: src/data/**/*.json
+alwaysApply: false
+---
+
+# Data File Conventions
+
+## General Rules
+- Every entity has a unique `id` field (string)
+- Cross-references use `id` strings, never array indices
+- Every entry has a `description` field (feeds the in-game Codex)
+- Data must be valid JSON — no comments, no trailing commas
+
+## elements.json
+Array of Element objects. Keyed by `symbol`. All values from real periodic table.
+```json
+{
+  "symbol": "Na",
+  "name": "Sodium",
+  "nameRu": "Натрий",
+  "atomicNumber": 11,
+  "atomicMass": 22.99,
+  "electronegativity": 0.93,
+  "category": "alkali-metal",
+  "state": "solid",
+  "color": "#c8c8c8",
+  "description": "Мягкий щелочной металл. Бурно реагирует с водой."
+}
+```
+
+## reactions.json
+Array of Reaction objects. Include science explanation and failure reasons.
+
+## Validation
+All JSON is loaded and type-checked at boot. Schema mismatches crash with clear errors — never silently ignore bad data.