chore: initialize repository with project docs and tooling

- Add persistent docs: PRD, functional design, architecture, repository structure, development guidelines, milestones

- Add brainstorming notes (docs/ideas/)

- Configure tooling: package.json, tsconfig, eslint, prettier, vitest

- Add opencode configuration (commands, skills, agents)

- Add .gitignore for node_modules, .env, data/, backups/, build outputs

tsconfig.json

@@ -0,0 +1,22 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "ESNext",
+    "lib": ["ES2022"],
+    "moduleResolution": "bundler",
+    "resolveJsonModule": true,
+    "allowSyntheticDefaultImports": true,
+    "esModuleInterop": true,
+    "outDir": "./dist",
+    "rootDir": "./src",
+    "strict": true,
+    "noUnusedLocals": true,
+    "noUnusedParameters": true,
+    "noFallthroughCasesInSwitch": true,
+    "skipLibCheck": true,
+    "forceConsistentCasingInFileNames": true,
+    "types": ["vitest/globals"]
+  },
+  "include": ["src/**/*"],
+  "exclude": ["node_modules", "dist"]
+}