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

packages/opencode/script/generate.ts

@@ -0,0 +1,14 @@
+import path from "path"
+import { fileURLToPath } from "url"
+
+const __filename = fileURLToPath(import.meta.url)
+const __dirname = path.dirname(__filename)
+const dir = path.resolve(__dirname, "..")
+
+process.chdir(dir)
+
+const modelsUrl = process.env.OPENCODE_MODELS_URL || "https://models.dev"
+export const modelsData = process.env.MODELS_DEV_API_JSON
+  ? await Bun.file(process.env.MODELS_DEV_API_JSON).text()
+  : await fetch(`${modelsUrl}/api.json`).then((x) => x.text())
+console.log("Loaded models.dev snapshot")