feat: 多数据库类型支持 — Redis/MongoDB/PostgreSQL 数据库+表浏览

后端:
- InstanceService.list_databases: Redis 通过 CONFIG GET databases 返回 db0-db15
- InstanceService.list_databases: MongoDB 通过 pymongo list_database_names 返回库列表
- InstanceService.list_tables: MongoDB 通过 list_collection_names 返回集合列表
- PostgreSQL 数据库/表列表已有支持

前端:
- TicketCreatePage: 所有数据库类型统一走后端 listDatabases API
- Redis 数据库改为下拉选择（db0-db15），替代手动输入
- 浏览面板: MySQL/PG 显示表结构+索引, MongoDB 显示集合, Redis 显示 Keys
- 新增 renderCollectionsTab 用于 MongoDB 集合浏览
- isMySQL 重命名为 isSQL, 新增 isMongo 类型判断

backend/app/services/instance_service.py

@@ -23,7 +23,7 @@ class InstanceService:
 
     @staticmethod
     async def list_databases(instance: Instance) -> List[str]:
-        """List databases for a MySQL instance."""
+        """List databases for the given instance type."""
         if instance.db_type == "mysql":
             conn = await aiomysql.connect(
                 host=instance.host, port=instance.port,
@@ -45,6 +45,31 @@ class InstanceService:
                 return [r["datname"] for r in rows]
             finally:
                 await conn.close()
+        elif instance.db_type == "redis":
+            from app.services.redis_connector import RedisConnector
+            conn = await RedisConnector.get_connection(instance)
+            try:
+                db_count = await conn.config_get("databases")
+                num = int(db_count.get("databases", 16))
+                return [f"db{i}" for i in range(num)]
+            finally:
+                await conn.close()
+        elif instance.db_type == "mongo":
+            from pymongo import MongoClient
+            pwd = instance.password
+            if pwd and not pwd.startswith("$"):
+                from app.core.crypto import decrypt_password
+                try:
+                    pwd = decrypt_password(pwd)
+                except Exception:
+                    pass
+            uri = f"mongodb://{instance.username}:{pwd}@{instance.host}:{instance.port}/admin"
+            client = MongoClient(uri, serverSelectionTimeoutMS=5000)
+            try:
+                dbs = client.list_database_names()
+                return [d for d in dbs if d not in ("admin", "config", "local")]
+            finally:
+                client.close()
         elif instance.db_type == "sqlite":
             return [instance.database or "main"]
         else:
@@ -80,6 +105,23 @@ class InstanceService:
                 return [dict(r) for r in rows]
             finally:
                 await conn.close()
+        elif instance.db_type == "mongo":
+            from pymongo import MongoClient
+            pwd = instance.password
+            if pwd and not pwd.startswith("$"):
+                from app.core.crypto import decrypt_password
+                try:
+                    pwd = decrypt_password(pwd)
+                except Exception:
+                    pass
+            uri = f"mongodb://{instance.username}:{pwd}@{instance.host}:{instance.port}/{database}"
+            client = MongoClient(uri, serverSelectionTimeoutMS=5000)
+            try:
+                db_obj = client[database]
+                colls = db_obj.list_collection_names()
+                return [{"name": c} for c in colls]
+            finally:
+                client.close()
         elif instance.db_type == "sqlite":
             import sqlite3
             db_path = instance.host