feat: 初始提交 - Code Server Bridge完整实现

- OAuth认证系统（Gitea + Lua扩展）
- Git自动化操作（本地/SSH远程）
- 实时进度WebSocket推送
- 现代化Tab界面UI
- Cobra CLI命令行（init/version/serve）
- 完整构建系统（Makefile + Taskfile）
- UPX压缩支持（体积减少70%）

internal/http/handlers/oauth.go

@@ -0,0 +1,84 @@
+package handlers
+
+import (
+	"cs-bridge/internal/http/middleware"
+	"cs-bridge/internal/oauth"
+	"net/http"
+
+	"github.com/go-chi/chi/v5"
+)
+
+func OauthLogin(mgr *oauth.Manager) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		name := chi.URLParam(r, "provider")
+		p, err := mgr.Get(name)
+		if err != nil {
+			http.Error(w, err.Error(), 404)
+			return
+		}
+
+		state := oauth.NewState()
+		session, err := middleware.GetSession(r)
+		session.Values["oauth_state"] = state
+		session.Values["oauth_provider"] = name
+		session.Save(r, w)
+
+		redirectURL, _ := p.AuthURL(state)
+
+		http.Redirect(w, r, redirectURL, http.StatusFound)
+	}
+}
+
+func OauthCallBack(mgr *oauth.Manager) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		name := chi.URLParam(r, "provider")
+		p, err := mgr.Get(name)
+		if err != nil {
+			http.Error(w, err.Error(), 404)
+			return
+		}
+
+		session, _ := middleware.GetSession(r)
+		expectedState, ok := session.Values["oauth_state"].(string)
+		if !ok {
+			http.Error(w, "missing oauth state", 400)
+			return
+		}
+
+		goState := r.URL.Query().Get("state")
+		if goState != expectedState {
+			http.Error(w, "invaild oauth state2", 400)
+			return
+		}
+
+		delete(session.Values, "oauth_state")
+
+		code := r.URL.Query().Get("code")
+		token, err := p.Exchange(code)
+		if err != nil {
+			http.Error(w, err.Error(), 404)
+			return
+		}
+
+		userInfo, err := p.UserInfo(token)
+		if err != nil {
+			http.Error(w, err.Error(), 500)
+			return
+		}
+
+		// 只保存用户ID，避免session过大
+		session.Values["uid"] = userInfo.UserId
+		session.Values["username"] = userInfo.Username
+
+		// 获取登录前保存的URL
+		redirectURL := "/"
+		if savedURL, ok := session.Values["redirect_after_login"].(string); ok && savedURL != "" {
+			redirectURL = savedURL
+			delete(session.Values, "redirect_after_login") // 使用后删除
+		}
+
+		session.Save(r, w)
+
+		http.Redirect(w, r, redirectURL, http.StatusFound)
+	}
+}