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/util/timeout.test.ts

@@ -0,0 +1,21 @@
+import { describe, expect, test } from "bun:test"
+import { withTimeout } from "../../src/util/timeout"
+
+describe("util.timeout", () => {
+  test("should resolve when promise completes before timeout", async () => {
+    const fastPromise = new Promise<string>((resolve) => {
+      setTimeout(() => resolve("fast"), 10)
+    })
+
+    const result = await withTimeout(fastPromise, 100)
+    expect(result).toBe("fast")
+  })
+
+  test("should reject when promise exceeds timeout", async () => {
+    const slowPromise = new Promise<string>((resolve) => {
+      setTimeout(() => resolve("slow"), 200)
+    })
+
+    await expect(withTimeout(slowPromise, 50)).rejects.toThrow("Operation timed out after 50ms")
+  })
+})