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/tui/test/fixture/tui-plugin.ts

@@ -0,0 +1,36 @@
+import type { TuiPluginApi } from "@opencode-ai/plugin/tui"
+import { RGBA } from "@opentui/core"
+import { createTuiResolvedConfig } from "./tui-runtime"
+
+type Opts = {
+  client?: TuiPluginApi["client"]
+  keymap?: TuiPluginApi["keymap"]
+  attention?: Partial<TuiPluginApi["attention"]>
+  event?: TuiPluginApi["event"]
+  state?: { session?: Partial<TuiPluginApi["state"]["session"]> }
+}
+
+export function createTuiPluginApi(opts: Opts = {}) {
+  const values = new Map<string, unknown>()
+  const color = RGBA.fromInts(200, 200, 200)
+  const dialog = { clear() {}, replace() {}, setSize() {}, size: "medium" as const, depth: 0, open: false }
+  return {
+    attention: { notify: async () => ({ ok: false, notification: false, sound: false }), ...opts.attention },
+    client: opts.client,
+    event: opts.event,
+    keymap: opts.keymap,
+    kv: {
+      get(name: string, fallback?: unknown) {
+        return values.has(name) ? values.get(name) : fallback
+      },
+      set(name: string, value: unknown) {
+        values.set(name, value)
+      },
+      ready: true,
+    },
+    state: { session: { get: () => undefined, ...opts.state?.session } },
+    theme: { current: new Proxy({}, { get: () => color }) },
+    tuiConfig: createTuiResolvedConfig(),
+    ui: { dialog },
+  } as unknown as TuiPluginApi
+}