chore: monorepo scaffolding — pnpm workspaces, biome, tsup, coding conventions

- packages/core, packages/cli, packages/daemon
- biome: noDefaultExport, useNodejsImportProtocol, noStaticOnlyClass
- docs/coding-conventions.md: 函数式优先，type over interface

package.json

@@ -0,0 +1,14 @@
+{
+  "name": "nerve",
+  "private": true,
+  "scripts": {
+    "build": "pnpm -r run build",
+    "check": "biome check .",
+    "format": "biome format --write ."
+  },
+  "devDependencies": {
+    "@biomejs/biome": "^1.9.0",
+    "tsup": "^8.0.0",
+    "typescript": "^5.5.0"
+  }
+}