refactor: migrate CLI from packages/server to apps/cli

Move the CLI application from packages/server/ to apps/cli/ to align
with the monorepo convention (apps/ for deployable applications,
packages/ for shared libraries). Rename package to @openchatlab/chatlab.

Also fix a bug in ensureToken() that used raw string manipulation to
write config.toml, causing duplicate token fields that corrupted the
TOML file. This led to config parse failures and user_data_dir being
overwritten with defaults. Now uses writeConfigField() for safe writes.

apps/cli/tsconfig.json

@@ -0,0 +1,17 @@
+{
+  "extends": "../../tsconfig.node.json",
+  "compilerOptions": {
+    "composite": true,
+    "noEmit": true
+  },
+  "include": [
+    "src/**/*.ts",
+    "../../packages/shared-types/**/*",
+    "../../packages/core/**/*",
+    "../../packages/node-runtime/**/*",
+    "../../packages/config/**/*",
+    "../../packages/parser/**/*",
+    "../../packages/tools/**/*",
+    "../../packages/sync/**/*"
+  ]
+}