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/test/fixture/plugin-meta-worker.ts

@@ -0,0 +1,19 @@
+const raw = process.argv[2]
+if (!raw) throw new Error("Missing worker payload")
+
+const value = JSON.parse(raw)
+if (!value || typeof value !== "object") {
+  throw new Error("Invalid worker payload")
+}
+
+const msg = Object.fromEntries(Object.entries(value))
+if (typeof msg.file !== "string" || typeof msg.spec !== "string" || typeof msg.target !== "string") {
+  throw new Error("Invalid worker payload")
+}
+if (typeof msg.id !== "string") throw new Error("Invalid worker payload")
+
+process.env.OPENCODE_PLUGIN_META_FILE = msg.file
+
+const { PluginMeta } = await import("../../src/plugin/meta")
+
+await PluginMeta.touch(msg.spec, msg.target, msg.id)