fix: add missing JavaScript for master trainers overview page

Resolves missing data on /master-trainer/trainers/ page by adding the JavaScript
file that handles AJAX loading of trainer statistics and table data.

✅ Changes:
- Created assets/js/hvac-master-trainers-overview.js
  - Handles AJAX calls to load trainer stats and filtered trainer lists
  - Implements filter change handlers for status, region, and search
  - Includes debounced search input for better UX
  - Initializes interactive table elements after load

- Updated includes/class-hvac-master-trainers-overview.php
  - Added enqueue_scripts() method to properly load the JS file
  - Registers wp_enqueue_scripts action hook
  - Detects master trainer pages via shortcode or template slug
  - Ensures jQuery dependency is met

The page was showing navigation and filters but no data because the JavaScript
to make AJAX calls to hvac_master_trainers_stats and hvac_master_trainers_filter
actions was completely missing.

Tested on staging and deployed to production.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

assets/js/hvac-master-trainers-overview.js

@@ -0,0 +1,156 @@
+/**
+ * Master Trainers Overview JavaScript
+ * Handles AJAX loading of trainer data and filtering
+ */
+
+(function($) {
+    'use strict';
+
+    // Wait for DOM and dependencies
+    $(document).ready(function() {
+        console.log('[HVAC] Master Trainers Overview: Initializing...');
+
+        // Check if we're on the trainers page
+        if ($('#hvac-master-trainers-overview').length === 0) {
+            console.log('[HVAC] Master Trainers Overview: Not on trainers page, skipping initialization');
+            return;
+        }
+
+        console.log('[HVAC] Master Trainers Overview: Found trainers container, loading data...');
+
+        // Load initial stats
+        loadTrainerStats();
+
+        // Load initial trainers list
+        loadTrainersList();
+
+        // Handle filter changes
+        $('#hvac-trainers-filters').on('submit', function(e) {
+            e.preventDefault();
+            loadTrainersList();
+        });
+
+        // Handle filter changes on select/input
+        $('#filter-status, #filter-region, #filter-search').on('change keyup', debounce(function() {
+            loadTrainersList();
+        }, 500));
+    });
+
+    /**
+     * Load trainer statistics
+     */
+    function loadTrainerStats() {
+        console.log('[HVAC] Loading trainer stats...');
+
+        $.ajax({
+            url: hvac_master_trainers_ajax.ajax_url,
+            type: 'POST',
+            data: {
+                action: 'hvac_master_trainers_stats',
+                nonce: hvac_master_trainers_ajax.nonce
+            },
+            success: function(response) {
+                console.log('[HVAC] Stats loaded successfully', response);
+
+                if (response.success && response.data.html) {
+                    $('#hvac-stats-tiles').html(response.data.html).show();
+                    $('#hvac-stats-loading').hide();
+                } else {
+                    console.error('[HVAC] Stats load failed:', response);
+                    $('#hvac-stats-loading').html('<p class="hvac-error">Failed to load statistics.</p>');
+                }
+            },
+            error: function(xhr, status, error) {
+                console.error('[HVAC] Stats AJAX error:', status, error);
+                $('#hvac-stats-loading').html('<p class="hvac-error">Error loading statistics.</p>');
+            }
+        });
+    }
+
+    /**
+     * Load trainers list with current filters
+     */
+    function loadTrainersList() {
+        console.log('[HVAC] Loading trainers list...');
+
+        // Show loading state
+        $('#hvac-trainers-loading').show();
+        $('#hvac-trainers-table-container').hide();
+
+        // Get filter values
+        var filters = {
+            action: 'hvac_master_trainers_filter',
+            nonce: hvac_master_trainers_ajax.nonce,
+            status: $('#filter-status').val() || 'all',
+            region: $('#filter-region').val() || '',
+            search: $('#filter-search').val() || ''
+        };
+
+        console.log('[HVAC] Filter values:', filters);
+
+        $.ajax({
+            url: hvac_master_trainers_ajax.ajax_url,
+            type: 'POST',
+            data: filters,
+            success: function(response) {
+                console.log('[HVAC] Trainers loaded successfully', response);
+
+                if (response.success && response.data.html) {
+                    $('#hvac-trainers-table-container').html(response.data.html).show();
+                    $('#hvac-trainers-loading').hide();
+
+                    // Initialize any interactive elements in the table
+                    initializeTrainerActions();
+                } else {
+                    console.error('[HVAC] Trainers load failed:', response);
+                    $('#hvac-trainers-loading').html('<p class="hvac-error">Failed to load trainers.</p>');
+                }
+            },
+            error: function(xhr, status, error) {
+                console.error('[HVAC] Trainers AJAX error:', status, error);
+                $('#hvac-trainers-loading').html('<p class="hvac-error">Error loading trainers.</p>');
+            }
+        });
+    }
+
+    /**
+     * Initialize trainer action buttons
+     */
+    function initializeTrainerActions() {
+        console.log('[HVAC] Initializing trainer actions...');
+
+        // Handle view profile buttons
+        $('.hvac-view-trainer').on('click', function(e) {
+            e.preventDefault();
+            var trainerId = $(this).data('trainer-id');
+            console.log('[HVAC] View trainer:', trainerId);
+            // Navigate to trainer profile
+            window.location.href = $(this).attr('href');
+        });
+
+        // Handle edit buttons
+        $('.hvac-edit-trainer').on('click', function(e) {
+            e.preventDefault();
+            var trainerId = $(this).data('trainer-id');
+            console.log('[HVAC] Edit trainer:', trainerId);
+            window.location.href = $(this).attr('href');
+        });
+
+        // Any other interactive elements...
+    }
+
+    /**
+     * Debounce function for search input
+     */
+    function debounce(func, wait) {
+        var timeout;
+        return function() {
+            var context = this, args = arguments;
+            clearTimeout(timeout);
+            timeout = setTimeout(function() {
+                func.apply(context, args);
+            }, wait);
+        };
+    }
+
+})(jQuery);

includes/class-hvac-master-trainers-overview.php

@@ -76,12 +76,39 @@ class HVAC_Master_Trainers_Overview {
 		// AJAX handlers for trainers overview
 		add_action( 'wp_ajax_hvac_master_trainers_filter', array( $this, 'ajax_filter_trainers' ) );
 		add_action( 'wp_ajax_hvac_master_trainers_stats', array( $this, 'ajax_get_stats' ) );
-		
+
 		// Shortcode for embedding trainers overview
 		add_shortcode( 'hvac_master_trainers', array( $this, 'render_trainers_overview' ) );
-		
+
-		// Add function for template integration  
+		// Add function for template integration
 		add_action( 'init', array( $this, 'register_template_functions' ) );
+
+		// Enqueue scripts for master trainers overview
+		add_action( 'wp_enqueue_scripts', array( $this, 'enqueue_scripts' ) );
+	}
+
+	/**
+	 * Enqueue scripts for master trainers overview
+	 */
+	public function enqueue_scripts() {
+		// Only enqueue on master trainers pages
+		if ( ! is_page() ) {
+			return;
+		}
+
+		global $post;
+		if ( ! $post || ( strpos( $post->post_content, '[hvac_master_trainers]' ) === false &&
+		     get_page_template_slug( $post->ID ) !== 'page-master-trainers.php' ) ) {
+			return;
+		}
+
+		wp_enqueue_script(
+			'hvac-master-trainers-overview',
+			HVAC_PLUGIN_URL . 'assets/js/hvac-master-trainers-overview.js',
+			array( 'jquery' ),
+			HVAC_VERSION,
+			true
+		);
 	}
 
 	/**