refactor(crdt): implement proxy-resilient Yjs dual-transport sync with indexeddb offline-first and debounced sqlite persistence

internal/ws/hub.go

@@ -62,6 +62,7 @@ type Hub struct {
 	sseUserRooms map[string]map[*SSEClient]bool
 	sseRooms     map[string]map[*SSEClient]bool
 	locks        map[string]*docLockItem
+	docRooms     map[string]*DocRoom
 	crdtStore    CRDTStore
 }
 
@@ -74,6 +75,7 @@ func NewHub() *Hub {
 		sseUserRooms: make(map[string]map[*SSEClient]bool),
 		sseRooms:     make(map[string]map[*SSEClient]bool),
 		locks:        make(map[string]*docLockItem),
+		docRooms:     make(map[string]*DocRoom),
 	}
 	go h.cleanupLocksLoop()
 	return h
@@ -811,23 +813,14 @@ func (c *Client) readPump() {
 					}
 				case "CRDT_JOIN":
 					c.hub.JoinRoom(c, "doc:"+docID)
-					if c.hub.crdtStore != nil {
-						stateBlob, updates, err := c.hub.crdtStore.GetDocumentCRDTState(docID)
-						if err == nil && (len(stateBlob) > 0 || len(updates) > 0) {
-							var b64Updates []string
-							for _, u := range updates {
-								b64Updates = append(b64Updates, base64.StdEncoding.EncodeToString(u))
-							}
-							b64State := ""
-							if len(stateBlob) > 0 {
-								b64State = base64.StdEncoding.EncodeToString(stateBlob)
-							}
-							c.SendEvent("CRDT_INIT", map[string]interface{}{
-								"docId":   docID,
-								"state":   b64State,
-								"updates": b64Updates,
-							})
-						}
+					room := c.hub.GetOrCreateDocRoom(docID)
+					b64State, b64Updates := room.GetInitialSnapshot()
+					if len(b64State) > 0 || len(b64Updates) > 0 {
+						c.SendEvent("CRDT_INIT", map[string]interface{}{
+							"docId":   docID,
+							"state":   b64State,
+							"updates": b64Updates,
+						})
 					}
 				case "CRDT_UPDATE":
 					var p struct {
@@ -835,15 +828,9 @@ func (c *Client) readPump() {
 					}
 					_ = json.Unmarshal(incoming.Payload, &p)
 					if p.Update != "" {
-						c.hub.BroadcastRoom("doc:"+docID, "CRDT_UPDATE", map[string]interface{}{
-							"docId":      docID,
-							"update":     p.Update,
-							"fromUserId": c.userID,
-						}, c)
-						if c.hub.crdtStore != nil {
-							if raw, err := base64.StdEncoding.DecodeString(p.Update); err == nil && len(raw) > 0 {
-								_ = c.hub.crdtStore.AppendDocumentCRDTUpdate(docID, raw, c.userID)
-							}
+						if raw, err := base64.StdEncoding.DecodeString(p.Update); err == nil && len(raw) > 0 {
+							room := c.hub.GetOrCreateDocRoom(docID)
+							room.ApplyUpdate(raw, c.userID, nil, nil)
 						}
 					}
 				case "CRDT_COMPACT":
@@ -851,13 +838,16 @@ func (c *Client) readPump() {
 						State string `json:"state"`
 					}
 					_ = json.Unmarshal(incoming.Payload, &p)
-					if p.State != "" && c.hub.crdtStore != nil {
+					if p.State != "" {
 						if raw, err := base64.StdEncoding.DecodeString(p.State); err == nil && len(raw) > 0 {
-							_ = c.hub.crdtStore.SaveDocumentCRDTState(docID, raw, c.userID)
+							room := c.hub.GetOrCreateDocRoom(docID)
+							room.CompactState(raw, c.userID)
 						}
 					}
 				case "CRDT_AWARENESS":
 					c.hub.BroadcastRoom("doc:"+docID, "CRDT_AWARENESS", incoming.Payload, c)
+					room := c.hub.GetOrCreateDocRoom(docID)
+					room.BroadcastAwareness(incoming.Payload, c.userID, nil, nil)
 				case "CRDT_LEAVE":
 					c.hub.LeaveRoom(c, "doc:"+docID)
 					c.hub.BroadcastRoom("doc:"+docID, "CRDT_AWARENESS_LEAVE", map[string]interface{}{