feat: 品牌替换 + 启动优化 + AGENTS.md 模板定制

- 品牌替换：OpenCode/opencode → AirCoding/aircoding（16+ 文件）
- Logo ASCII art：修复 left/right 行数不匹配导致的启动崩溃
- 启动诊断：添加 OPENCODE_PRINT_TIMING 计时探针
- dev 模式默认 --pure 跳过外部插件加载
- AGENTS.md 模板：追加 AirCoding 多 Agent 专项段落
- architect prompt + plugin：强化 AGENTS.md 产出验证

turbo.json

@@ -0,0 +1,25 @@
+{
+  "$schema": "https://v2-8-13.turborepo.dev/schema.json",
+  "globalEnv": ["CI", "OPENCODE_DISABLE_SHARE"],
+  "globalPassThroughEnv": ["CI", "OPENCODE_DISABLE_SHARE"],
+  "tasks": {
+    "typecheck": {},
+    "build": {
+      "dependsOn": [],
+      "outputs": ["dist/**"]
+    },
+    "opencode#test": {
+      "dependsOn": ["^build"],
+      "outputs": [],
+      "passThroughEnv": ["*"]
+    },
+    "@opencode-ai/app#test": {
+      "dependsOn": ["^build"],
+      "outputs": []
+    },
+    "@opencode-ai/ui#test": {
+      "dependsOn": ["^build"],
+      "outputs": []
+    }
+  }
+}