fix: normalize custom command handling and improve project settings loading

- Updated the `DevServerService` to normalize custom commands by trimming whitespace and treating empty strings as undefined.
- Refactored the `DevServerSection` component to utilize TanStack Query for fetching project settings, improving data handling and error management.
- Enhanced the save functionality to use mutation hooks for updating project settings, streamlining the save process and ensuring better state management.

These changes enhance the reliability and user experience when configuring development server commands.

apps/server/src/services/dev-server-service.ts

@@ -358,16 +358,19 @@ class DevServerService {
     // Determine the dev command to use
     let devCommand: { cmd: string; args: string[] };
 
-    if (customCommand) {
+    // Normalize custom command: trim whitespace and treat empty strings as undefined
+    const normalizedCustomCommand = customCommand?.trim();
+
+    if (normalizedCustomCommand) {
       // Use the provided custom command
-      devCommand = this.parseCustomCommand(customCommand);
+      devCommand = this.parseCustomCommand(normalizedCustomCommand);
       if (!devCommand.cmd) {
         return {
           success: false,
           error: 'Invalid custom command: command cannot be empty',
         };
       }
-      logger.debug(`Using custom command: ${customCommand}`);
+      logger.debug(`Using custom command: ${normalizedCustomCommand}`);
     } else {
       // Check for package.json when auto-detecting
       const packageJsonPath = path.join(worktreePath, 'package.json');