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/src/cli/cmd/debug/snapshot.ts

@@ -0,0 +1,50 @@
+import { Effect } from "effect"
+import { Snapshot } from "../../../snapshot"
+import { effectCmd } from "../../effect-cmd"
+import { cmd } from "../cmd"
+
+export const SnapshotCommand = cmd({
+  command: "snapshot",
+  describe: "snapshot debugging utilities",
+  builder: (yargs) => yargs.command(TrackCommand).command(PatchCommand).command(DiffCommand).demandCommand(),
+  async handler() {},
+})
+
+const TrackCommand = effectCmd({
+  command: "track",
+  describe: "track current snapshot state",
+  handler: Effect.fn("Cli.debug.snapshot.track")(function* () {
+    const out = yield* Snapshot.Service.use((svc) => svc.track())
+    console.log(out)
+  }),
+})
+
+const PatchCommand = effectCmd({
+  command: "patch <hash>",
+  describe: "show patch for a snapshot hash",
+  builder: (yargs) =>
+    yargs.positional("hash", {
+      type: "string",
+      description: "hash",
+      demandOption: true,
+    }),
+  handler: Effect.fn("Cli.debug.snapshot.patch")(function* (args) {
+    const out = yield* Snapshot.Service.use((svc) => svc.patch(args.hash))
+    console.log(out)
+  }),
+})
+
+const DiffCommand = effectCmd({
+  command: "diff <hash>",
+  describe: "show diff for a snapshot hash",
+  builder: (yargs) =>
+    yargs.positional("hash", {
+      type: "string",
+      description: "hash",
+      demandOption: true,
+    }),
+  handler: Effect.fn("Cli.debug.snapshot.diff")(function* (args) {
+    const out = yield* Snapshot.Service.use((svc) => svc.diff(args.hash))
+    console.log(out)
+  }),
+})