Add dynamic log level reload support to server

Introduces tracing_subscriber::reload to enable dynamic log level changes at runtime. Updates the main server initialization and ServiceRegister to accept and store a log handle. Refactors related code to support this feature and removes disabled state from developer UI log level selectors.

app/ui/plugins/developer.tsx

@@ -52,7 +52,6 @@ const Developer: React.FC = () => {
             formApi.setValue('LOGGING.root.handlers', ['console'])
           }}
           showClear={true}
-          disabled
         >
           <Select.Option value="DEBUG">DEBUG</Select.Option>
           <Select.Option value="INFO">INFO</Select.Option>
@@ -73,7 +72,6 @@ const Developer: React.FC = () => {
             formApi.setValue('LOGGING.loggers.biliup.handlers', ['file'])
           }}
           showClear={true}
-          disabled
         >
           <Select.Option value="DEBUG">DEBUG</Select.Option>
           <Select.Option value="INFO">INFO</Select.Option>