feat: implement Redis Streams support with stream checkpoints and update history

- Added Redis Streams operations to the message bus interface and implementation.
- Introduced StreamCheckpoint model to track last processed stream entry per document.
- Implemented UpsertStreamCheckpoint and GetStreamCheckpoint methods in the Postgres store.
- Created document_update_history table for storing update payloads for recovery and replay.
- Developed update persist worker to handle Redis Stream updates and persist them to Postgres.
- Enhanced Docker Compose configuration for Redis with persistence.
- Updated frontend API to support fetching document state with optional share token.
- Added connection stability monitoring in the Yjs document hook.

backend/internal/messagebus/interface.go

@@ -2,6 +2,7 @@ package messagebus
 
 import (
 	"context"
+	"time"
 )
 
 // MessageBus abstracts message distribution across server instances
@@ -33,6 +34,72 @@ type MessageBus interface {
 
 	// Close gracefully shuts down the message bus
 	Close() error
+
+	// ========== Redis Streams Operations ==========
+
+	// XAdd adds a new entry to a stream with optional MAXLEN trimming
+	XAdd(ctx context.Context, stream string, maxLen int64, approx bool, values map[string]interface{}) (string, error)
+
+	// XReadGroup reads messages from a stream using a consumer group
+	XReadGroup(ctx context.Context, group, consumer string, streams []string, count int64, block time.Duration) ([]StreamMessage, error)
+
+	// XAck acknowledges one or more messages from a consumer group
+	XAck(ctx context.Context, stream, group string, ids ...string) (int64, error)
+
+	// XGroupCreate creates a new consumer group for a stream
+	XGroupCreate(ctx context.Context, stream, group, start string) error
+
+	// XGroupCreateMkStream creates a consumer group and the stream if it doesn't exist
+	XGroupCreateMkStream(ctx context.Context, stream, group, start string) error
+
+	// XPending returns pending messages information for a consumer group
+	XPending(ctx context.Context, stream, group string) (*PendingInfo, error)
+
+	// XClaim claims pending messages from a consumer group
+	XClaim(ctx context.Context, stream, group, consumer string, minIdleTime time.Duration, ids ...string) ([]StreamMessage, error)
+
+	// XAutoClaim claims pending messages automatically (Redis >= 6.2)
+	// Returns claimed messages and next start ID.
+	XAutoClaim(ctx context.Context, stream, group, consumer string, minIdleTime time.Duration, start string, count int64) ([]StreamMessage, string, error)
+
+	// XRange reads a range of messages from a stream
+	XRange(ctx context.Context, stream, start, end string) ([]StreamMessage, error)
+
+	// XTrimMinID trims a stream to a minimum ID (time-based retention)
+	XTrimMinID(ctx context.Context, stream, minID string) (int64, error)
+
+	// Incr increments a counter atomically (for sequence numbers)
+	Incr(ctx context.Context, key string) (int64, error)
+
+	// ========== Sorted Set (ZSET) Operations ==========
+
+	// ZAdd adds a member with a score to a sorted set (used for active-stream tracking)
+	ZAdd(ctx context.Context, key string, score float64, member string) error
+
+	// ZRangeByScore returns members with scores between min and max
+	ZRangeByScore(ctx context.Context, key string, min, max float64) ([]string, error)
+
+	// ZRemRangeByScore removes members with scores between min and max
+	ZRemRangeByScore(ctx context.Context, key string, min, max float64) (int64, error)
+
+	// Distributed lock helpers (used by background workers)
+	AcquireLock(ctx context.Context, key string, ttl time.Duration) (bool, error)
+	RefreshLock(ctx context.Context, key string, ttl time.Duration) (bool, error)
+	ReleaseLock(ctx context.Context, key string) error
+}
+
+// StreamMessage represents a message from a Redis Stream
+type StreamMessage struct {
+	ID     string
+	Values map[string]interface{}
+}
+
+// PendingInfo contains information about pending messages in a consumer group
+type PendingInfo struct {
+	Count     int64
+	Lower     string
+	Upper     string
+	Consumers map[string]int64
 }
 
 // LocalMessageBus is a no-op implementation for single-server mode
@@ -78,3 +145,73 @@ func (l *LocalMessageBus) IsHealthy() bool {
 func (l *LocalMessageBus) Close() error {
 	return nil
 }
+
+// ========== Redis Streams Operations (No-op for local mode) ==========
+
+func (l *LocalMessageBus) XAdd(ctx context.Context, stream string, maxLen int64, approx bool, values map[string]interface{}) (string, error) {
+	return "0-0", nil
+}
+
+func (l *LocalMessageBus) XReadGroup(ctx context.Context, group, consumer string, streams []string, count int64, block time.Duration) ([]StreamMessage, error) {
+	return nil, nil
+}
+
+func (l *LocalMessageBus) XAck(ctx context.Context, stream, group string, ids ...string) (int64, error) {
+	return 0, nil
+}
+
+func (l *LocalMessageBus) XGroupCreate(ctx context.Context, stream, group, start string) error {
+	return nil
+}
+
+func (l *LocalMessageBus) XGroupCreateMkStream(ctx context.Context, stream, group, start string) error {
+	return nil
+}
+
+func (l *LocalMessageBus) XPending(ctx context.Context, stream, group string) (*PendingInfo, error) {
+	return &PendingInfo{}, nil
+}
+
+func (l *LocalMessageBus) XClaim(ctx context.Context, stream, group, consumer string, minIdleTime time.Duration, ids ...string) ([]StreamMessage, error) {
+	return nil, nil
+}
+
+func (l *LocalMessageBus) XAutoClaim(ctx context.Context, stream, group, consumer string, minIdleTime time.Duration, start string, count int64) ([]StreamMessage, string, error) {
+	return nil, "0-0", nil
+}
+
+func (l *LocalMessageBus) XRange(ctx context.Context, stream, start, end string) ([]StreamMessage, error) {
+	return nil, nil
+}
+
+func (l *LocalMessageBus) XTrimMinID(ctx context.Context, stream, minID string) (int64, error) {
+	return 0, nil
+}
+
+func (l *LocalMessageBus) Incr(ctx context.Context, key string) (int64, error) {
+	return 0, nil
+}
+
+func (l *LocalMessageBus) ZAdd(ctx context.Context, key string, score float64, member string) error {
+	return nil
+}
+
+func (l *LocalMessageBus) ZRangeByScore(ctx context.Context, key string, min, max float64) ([]string, error) {
+	return nil, nil
+}
+
+func (l *LocalMessageBus) ZRemRangeByScore(ctx context.Context, key string, min, max float64) (int64, error) {
+	return 0, nil
+}
+
+func (l *LocalMessageBus) AcquireLock(ctx context.Context, key string, ttl time.Duration) (bool, error) {
+	return true, nil
+}
+
+func (l *LocalMessageBus) RefreshLock(ctx context.Context, key string, ttl time.Duration) (bool, error) {
+	return true, nil
+}
+
+func (l *LocalMessageBus) ReleaseLock(ctx context.Context, key string) error {
+	return nil
+}