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

patches/@ff-labs%2Ffff-bun@0.9.3.patch

@@ -0,0 +1,31 @@
+diff --git a/src/download.ts b/src/download.ts
+index 3454256..6dca25a 100644
+--- a/src/download.ts
++++ b/src/download.ts
+@@ -7,7 +7,7 @@
+  */
+ 
++declare const FFF_LIBC: "gnu" | "musl";
+ import { existsSync } from "node:fs";
+-import { createRequire } from "node:module";
+ import { dirname, join } from "node:path";
+ import { fileURLToPath } from "node:url";
+ import { getLibFilename, getNpmPackageName } from "./platform";
+@@ -54,14 +54,10 @@ export function binaryExists(): boolean {
+  * in the same directory.
+  */
+ function resolveFromNpmPackage(): string | null {
+-  const packageName = getNpmPackageName();
+-
+   try {
+-    // Use createRequire to resolve the platform package's location
+-    const require = createRequire(join(getPackageDir(), "package.json"));
+-    const packageJsonPath = require.resolve(`${packageName}/package.json`);
+-    const packageDir = dirname(packageJsonPath);
+-    const binaryPath = join(packageDir, getLibFilename());
++    const binaryPath = require(
++      `@ff-labs/fff-bin-${process.platform === "linux" ? `linux-${process.arch}-${typeof FFF_LIBC === "string" ? FFF_LIBC : getNpmPackageName().endsWith("musl") ? "musl" : "gnu"}` : `${process.platform}-${process.arch}`}/${process.platform === "win32" ? "fff_c.dll" : process.platform === "darwin" ? "libfff_c.dylib" : "libfff_c.so"}`,
++    );
+ 
+     if (existsSync(binaryPath)) {
+       return binaryPath;