feat: ship loose-offline dbsync (validate, agent push, LWW audit)

Add UUID/FK channel checks, agent whitelist/push APIs, bindings, super-admin LWW audit with rollback, reconcile rate limits, and sync docs. Default customers stay opt-in; company conflict UI is removed.

Co-authored-by: Cursor <cursoragent@cursor.com>

platform/internal/handler/sync_binding.go

@@ -0,0 +1,50 @@
+package handler
+
+import (
+	"encoding/json"
+	"net/http"
+
+	"aijianzhan/platform/internal/authx"
+	"aijianzhan/platform/internal/dbsync"
+	"aijianzhan/platform/internal/svc"
+
+	"github.com/zeromicro/go-zero/rest/httpx"
+)
+
+func syncBindingsListHandler(svcCtx *svc.ServiceContext) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		if !requireDBSync(svcCtx, w) {
+			return
+		}
+		localID := r.URL.Query().Get("local_database_id")
+		list, err := svcCtx.DBSync.Store().ListBindings(syncTenantID(r), localID)
+		if err != nil {
+			authx.WriteError(w, http.StatusBadRequest, err.Error())
+			return
+		}
+		httpx.OkJson(w, map[string]any{"items": list})
+	}
+}
+
+func syncBindingsEnsureHandler(svcCtx *svc.ServiceContext) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		if !requireDBSync(svcCtx, w) {
+			return
+		}
+		var body dbsync.Binding
+		if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
+			authx.WriteError(w, http.StatusBadRequest, err.Error())
+			return
+		}
+		body.TenantID = syncTenantID(r)
+		if body.UserID == 0 {
+			body.UserID = authx.UserID(r.Context())
+		}
+		saved, err := svcCtx.DBSync.Store().EnsureBinding(body)
+		if err != nil {
+			authx.WriteError(w, http.StatusBadRequest, err.Error())
+			return
+		}
+		httpx.OkJson(w, saved)
+	}
+}