feat: add GitHub Token device authorization

app/api/dependencies/github.py

@@ -0,0 +1,16 @@
+"""GitHub 授权 API 的应用服务依赖。"""
+
+from fastapi import Depends, HTTPException
+
+from app.api.context import get_host_runtime
+from app.application.github_auth import GithubAuthService
+from app.startup.composition.context import HostRuntime
+
+
+def get_github_auth_service(
+    runtime: HostRuntime = Depends(get_host_runtime),
+) -> GithubAuthService:
+    """从宿主运行时取得已装配的 GitHub 授权应用服务。"""
+    if runtime.system.github_auth is None:
+        raise HTTPException(status_code=503, detail="GitHub 授权服务尚未初始化")
+    return runtime.system.github_auth