test(channels): add comprehensive test suites for channel adapters

- Add ChannelBase, GroupGate, SenderGate, SessionRouter tests
- Add DingTalk markdown utility tests
- Add Weixin media and send helper tests
- Add CLI channel config-utils and pidfile tests
- Configure vitest for all channel packages
- Exclude test files from TypeScript build

Tests cover attachment handling, block streaming, gating policies,
session routing, markdown conversion, config parsing, and service management.

Co-authored-by: Qwen-Coder <qwen-coder@alibabacloud.com>

packages/channels/dingtalk/tsconfig.json

@@ -5,6 +5,6 @@
     "rootDir": "src"
   },
   "include": ["src/**/*.ts"],
-  "exclude": ["node_modules", "dist"],
+  "exclude": ["node_modules", "dist", "src/**/*.test.ts"],
   "references": [{ "path": "../base" }]
 }