feat: add auto-refresh polling for memo feeds

proto/api/v1/instance_service.proto

@@ -102,6 +102,10 @@ message InstanceSetting {
     bool disallow_change_username = 8;
     // disallow_change_nickname disallows changing nickname.
     bool disallow_change_nickname = 9;
+    // enable_explore_auto_refresh enables auto-refresh on Explore page. Default: true.
+    bool enable_explore_auto_refresh = 10;
+    // min_auto_refresh_interval is the minimum auto-refresh interval in seconds. Default: 1.
+    int32 min_auto_refresh_interval = 11;
 
     // Custom profile configuration for instance branding.
     message CustomProfile {

proto/api/v1/user_service.proto

@@ -416,6 +416,8 @@ message UserSetting {
     // This references a CSS file in the web/public/themes/ directory.
     // If not set, the default theme will be used.
     string theme = 4 [(google.api.field_behavior) = OPTIONAL];
+    // Auto-refresh interval in seconds. 0 = disabled, default = 30.
+    int32 auto_refresh_interval = 5 [(google.api.field_behavior) = OPTIONAL];
   }
 
   // User authentication sessions configuration.