feat: 添加 Redis Docker 容器编排及三级存储架构

- docker-compose.yml 新增 Redis 服务及 camtalk-net 桥接网络
- 实现 TieredManager 三级存储（L1 内存 → L2 Redis → L3 PostgreSQL）
- config.go 新增 Redis/Persistence 配置类型及环境变量绑定
- 修复 CAMTALK_REDIS_ADDR 环境变量未被 Viper 绑定的问题
- .env.example 更新为三级存储配置并标注开发/部署地址差异

docker-compose.yml

@@ -20,11 +20,18 @@ services:
     env_file:
       - /opt/camtalk/.env
     environment:
-      - CAMTALK_STORAGE_DRIVER=${CAMTALK_STORAGE_DRIVER:-postgres}
+      # 三级存储配置
+      - CAMTALK_STORAGE_REDIS_ENABLED=${CAMTALK_STORAGE_REDIS_ENABLED:-true}
+      - CAMTALK_STORAGE_PERSISTENCE_ENABLED=${CAMTALK_STORAGE_PERSISTENCE_ENABLED:-true}
+      - CAMTALK_STORAGE_PERSISTENCE_DRIVER=${CAMTALK_STORAGE_PERSISTENCE_DRIVER:-postgres}
       - CAMTALK_STORAGE_DSN=postgres://${POSTGRES_USER}:${POSTGRES_PASSWORD}@postgres:5432/camtalk?sslmode=disable
+      - CAMTALK_REDIS_ADDR=redis:6379
+      - CAMTALK_REDIS_PASSWORD=${CAMTALK_REDIS_PASSWORD:-}
     depends_on:
       postgres:
         condition: service_healthy
+      redis:
+        condition: service_healthy
     networks:
       - camtalk-net
     restart: unless-stopped
@@ -48,8 +55,24 @@ services:
       retries: 10
     restart: unless-stopped
 
+  redis:
+    image: docker.m.daocloud.io/library/redis:7-alpine
+    container_name: camtalk-redis
+    command: redis-server --appendonly yes --requirepass ${CAMTALK_REDIS_PASSWORD:-}
+    volumes:
+      - redisdata:/data
+    networks:
+      - camtalk-net
+    healthcheck:
+      test: ["CMD", "redis-cli", "-a", "${CAMTALK_REDIS_PASSWORD:-}", "ping"]
+      interval: 5s
+      timeout: 3s
+      retries: 10
+    restart: unless-stopped
+
 volumes:
   pgdata:
+  redisdata:
 
 networks:
   camtalk-net: