cdrop — 跨 OS 剪贴板与文件传输服务

Commilitia Drop：自托管的跨设备剪贴板同步与点对点文件传输。

- 后端 Go（chi / SQLite WAL / SSE Hub / WebRTC signaling + 状态机 / Relay ring buffer），编译进单个 distroless 镜像（前端 go:embed）。
- 前端 React + TanStack Router + Zustand，自实现 SSE + WebRTC P2P，NAT 受阻时回退服务端中继；聚珍（Juzhen）CJK 综合排版。
- 桌面端 Wails v2（macOS / Windows），瘦客户端复用 web。
- 鉴权 OIDC PKCE（自建 Casdoor 等），refresh_token 信封加密存系统密钥库；iOS Shortcut 用 HS256 scoped token。

架构文档与变更记录见 docs 分支（PROJECT_BRIEF / FRONTEND_DESIGN / CHANGELOG）。

本次为公开发布初始提交：完整开发历史（含部署细节）留存于私有归档，公开仓库自此干净起步。

internal/httpapi/transfer.go

@@ -0,0 +1,94 @@
+package httpapi
+
+import (
+	"encoding/json"
+	"errors"
+	"net/http"
+
+	"github.com/go-chi/chi/v5"
+
+	"commilitia.net/cdrop/internal/jwtauth"
+	"commilitia.net/cdrop/internal/transfer"
+)
+
+type initReq struct {
+	ReceiverName string `json:"receiver_name"`
+	FileName     string `json:"file_name"`
+	FileSize     int64  `json:"file_size"`
+	FileSHA256   string `json:"file_sha256,omitempty"`
+}
+
+type initResp struct {
+	SessionID string `json:"session_id"`
+}
+
+func (s *Server) handleTransferInit(w http.ResponseWriter, r *http.Request) {
+	claims, _ := jwtauth.ClaimsFromContext(r.Context())
+	sender, _ := jwtauth.DeviceNameFromContext(r.Context())
+
+	var req initReq
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		writeJSON(w, http.StatusBadRequest, map[string]string{"error": "invalid json"})
+		return
+	}
+
+	id, err := s.transfers.Init(r.Context(), transfer.InitParams{
+		UserID:       claims.UserID,
+		SenderName:   sender,
+		ReceiverName: req.ReceiverName,
+		FileName:     req.FileName,
+		FileSize:     req.FileSize,
+		FileSHA256:   req.FileSHA256,
+	})
+	if err != nil {
+		writeJSON(w, http.StatusBadRequest, map[string]string{"error": err.Error()})
+		return
+	}
+	writeJSON(w, http.StatusOK, initResp{SessionID: id})
+}
+
+// handleTransferTransition is the shared body for accept / cancel / fallback /
+// done / fail. The target state and any side-fields are bound by the route.
+type transitionReq struct {
+	Reason           string `json:"reason,omitempty"`
+	BytesTransferred int64  `json:"bytes_transferred,omitempty"`
+}
+
+func (s *Server) transitionHandler(target, mode string) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		claims, _ := jwtauth.ClaimsFromContext(r.Context())
+		id := chi.URLParam(r, "id")
+		if id == "" {
+			writeJSON(w, http.StatusBadRequest, map[string]string{"error": "missing id"})
+			return
+		}
+
+		var req transitionReq
+		if r.ContentLength > 0 {
+			if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+				writeJSON(w, http.StatusBadRequest, map[string]string{"error": "invalid json"})
+				return
+			}
+		}
+
+		err := s.transfers.Transition(
+			r.Context(), claims.UserID, id, target,
+			mode, req.Reason, req.BytesTransferred,
+		)
+		switch {
+		case err == nil:
+			w.WriteHeader(http.StatusNoContent)
+		case errors.Is(err, transfer.ErrNotFound):
+			writeJSON(w, http.StatusNotFound, map[string]string{"error": "not found"})
+		case errors.Is(err, transfer.ErrForbidden):
+			writeJSON(w, http.StatusForbidden, map[string]string{"error": "forbidden"})
+		case errors.Is(err, transfer.ErrInvalidTransition):
+			writeJSON(w, http.StatusConflict, map[string]string{"error": err.Error()})
+		case errors.Is(err, transfer.ErrRelayUnavailable):
+			writeJSON(w, http.StatusServiceUnavailable,
+				map[string]string{"error": "relay unavailable, retry later"})
+		default:
+			writeJSON(w, http.StatusInternalServerError, map[string]string{"error": err.Error()})
+		}
+	}
+}