Initial scaffold: tooling, plan, task briefs

- pnpm 10 workspace + TypeScript strict + ESLint flat + Prettier
- CLAUDE.md as canonical brief
- docs/tasks/ — 22 task briefs broken out by phase for sub-sessions
- docs/decisions/ — ADR scaffold

Implements task 01 (repo-init).

eslint.config.mjs

@@ -0,0 +1,33 @@
+import js from "@eslint/js";
+import tseslint from "typescript-eslint";
+import globals from "globals";
+
+export default tseslint.config(
+  {
+    ignores: [
+      "node_modules/**",
+      ".next/**",
+      "dist/**",
+      "drizzle/**",
+      "*.config.js",
+      "*.config.mjs",
+      "*.config.cjs",
+    ],
+  },
+  js.configs.recommended,
+  ...tseslint.configs.recommended,
+  {
+    languageOptions: {
+      globals: {
+        ...globals.node,
+        ...globals.browser,
+      },
+    },
+    rules: {
+      "@typescript-eslint/no-unused-vars": [
+        "error",
+        { argsIgnorePattern: "^_", varsIgnorePattern: "^_" },
+      ],
+    },
+  },
+);