feat: implement Redis-based message bus and awareness management

- Added RedisMessageBus for message distribution using Redis Pub/Sub.
- Introduced LocalMessageBus as a no-op implementation for single-server mode.
- Created messagebus interface for abstraction of message distribution.
- Implemented awareness management methods: SetAwareness, GetAllAwareness, DeleteAwareness, and ClearAllAwareness.
- Added logger utility for structured logging with zap.
- Refactored SniffYjsClientIDs and MakeYjsDeleteMessage functions for improved readability.

backend/go.mod

@@ -11,7 +11,9 @@ require (
 	github.com/gorilla/websocket v1.5.3
 	github.com/joho/godotenv v1.5.1
 	github.com/lib/pq v1.10.9
+	github.com/redis/go-redis/v9 v9.17.3
 	github.com/stretchr/testify v1.11.1
+	go.uber.org/zap v1.27.1
 	golang.org/x/oauth2 v0.34.0
 )
 
@@ -19,8 +21,10 @@ require (
 	cloud.google.com/go/compute/metadata v0.3.0 // indirect
 	github.com/bytedance/sonic v1.14.0 // indirect
 	github.com/bytedance/sonic/loader v0.3.0 // indirect
+	github.com/cespare/xxhash/v2 v2.3.0 // indirect
 	github.com/cloudwego/base64x v0.1.6 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f // indirect
 	github.com/gabriel-vasile/mimetype v1.4.9 // indirect
 	github.com/gin-contrib/sse v1.1.0 // indirect
 	github.com/go-playground/locales v0.14.1 // indirect
@@ -29,7 +33,6 @@ require (
 	github.com/goccy/go-yaml v1.18.0 // indirect
 	github.com/json-iterator/go v1.1.12 // indirect
 	github.com/klauspost/cpuid/v2 v2.3.0 // indirect
-	github.com/kr/text v0.2.0 // indirect
 	github.com/leodido/go-urn v1.4.0 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
@@ -41,6 +44,7 @@ require (
 	github.com/twitchyliquid64/golang-asm v0.15.1 // indirect
 	github.com/ugorji/go/codec v1.3.0 // indirect
 	go.uber.org/mock v0.5.0 // indirect
+	go.uber.org/multierr v1.10.0 // indirect
 	golang.org/x/arch v0.20.0 // indirect
 	golang.org/x/crypto v0.40.0 // indirect
 	golang.org/x/mod v0.25.0 // indirect