feat(02-04): implement WP-Admin redirect for providers

- Create DDHH_JM_Access_Control class with redirect logic
- Redirect providers from WP-Admin to dashboard page
- Preserve access to profile.php for password/email changes
- Preserve access to admin-ajax.php for AJAX requests
- Integrate access control hooks in main plugin class

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

includes/class-ddhh-job-manager.php

@@ -58,5 +58,8 @@ class DDHH_JM_Job_Manager {
 
 		// Initialize dashboard
 		add_action( 'init', array( 'DDHH_JM_Dashboard', 'init' ) );
+
+		// Initialize access control
+		add_action( 'init', array( 'DDHH_JM_Access_Control', 'setup_hooks' ) );
 	}
 }