docs: add project docs, GitHub DX, fire-tools stamp

- CLAUDE.md with commands, structure, key constraints
- .claude/rules/ coding standards + workflows
- docs/architecture.md with design decisions
- .github/ CI workflow, issue templates, PR template
- LICENSE (MIT)
- .fire-tools.json initialization stamp
- README.md rewritten with features, quick start, stack table

.fire-tools.json

@@ -0,0 +1,12 @@
+{
+  "fire_tools_version": "0.1.0",
+  "initialized_at": "2026-04-24T00:00:00Z",
+  "profile": "other",
+  "features": ["pnpm", "biome", "vitest", "zod"],
+  "deviations": [
+    "No SQL database (Honcho API handles persistence)",
+    "No turborepo (single package)",
+    "No commitlint/husky (small solo project)",
+    "No semantic-release (not publishing to npm)"
+  ]
+}