feat: Hide future months from month range filter and table columns

Compare against current YYYY-MM to exclude future months from the
from/to selectors, default selection, and table column display.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

templates/adults.html

@@ -923,6 +923,8 @@
         }
 
         // Month range filter
+        var maxMonthIdx;
+
         function applyMonthFilter() {
             var fromIdx = parseInt(document.getElementById('fromMonth').value);
             var toIdx = parseInt(document.getElementById('toMonth').value);
@@ -940,17 +942,41 @@
             var fromSelect = document.getElementById('fromMonth');
             var toSelect = document.getElementById('toMonth');
             fromSelect.value = 0;
-            toSelect.value = fromSelect.options.length - 1;
+            toSelect.value = maxMonthIdx;
             applyMonthFilter();
         }
 
-        // Set defaults (last 5 months) and apply on load
+        // Remove future months from selects, set defaults, apply on load
         (function() {
+            var now = new Date();
+            var currentMonth = now.getFullYear() + '-' + String(now.getMonth() + 1).padStart(2, '0');
+            maxMonthIdx = sortedMonths.length - 1;
+            for (var i = 0; i < sortedMonths.length; i++) {
+                if (sortedMonths[i] > currentMonth) {
+                    maxMonthIdx = i - 1;
+                    break;
+                }
+            }
+
             var fromSelect = document.getElementById('fromMonth');
             var toSelect = document.getElementById('toMonth');
-            var defaultFrom = Math.max(0, fromSelect.options.length - 5);
+
+            // Remove future month options
+            for (var i = fromSelect.options.length - 1; i > maxMonthIdx; i--) {
+                fromSelect.remove(i);
+                toSelect.remove(i);
+            }
+
+            // Hide future month columns permanently
+            document.querySelectorAll('[data-month-idx]').forEach(function(el) {
+                if (parseInt(el.getAttribute('data-month-idx')) > maxMonthIdx) {
+                    el.classList.add('month-hidden');
+                }
+            });
+
+            var defaultFrom = Math.max(0, maxMonthIdx - 4);
             fromSelect.value = defaultFrom;
-            toSelect.value = fromSelect.options.length - 1;
+            toSelect.value = maxMonthIdx;
             applyMonthFilter();
         })();
     </script>

templates/juniors.html

@@ -904,6 +904,8 @@
         }
 
         // Month range filter
+        var maxMonthIdx;
+
         function applyMonthFilter() {
             var fromIdx = parseInt(document.getElementById('fromMonth').value);
             var toIdx = parseInt(document.getElementById('toMonth').value);
@@ -921,17 +923,41 @@
             var fromSelect = document.getElementById('fromMonth');
             var toSelect = document.getElementById('toMonth');
             fromSelect.value = 0;
-            toSelect.value = fromSelect.options.length - 1;
+            toSelect.value = maxMonthIdx;
             applyMonthFilter();
         }
 
-        // Set defaults (last 5 months) and apply on load
+        // Remove future months from selects, set defaults, apply on load
         (function() {
+            var now = new Date();
+            var currentMonth = now.getFullYear() + '-' + String(now.getMonth() + 1).padStart(2, '0');
+            maxMonthIdx = sortedMonths.length - 1;
+            for (var i = 0; i < sortedMonths.length; i++) {
+                if (sortedMonths[i] > currentMonth) {
+                    maxMonthIdx = i - 1;
+                    break;
+                }
+            }
+
             var fromSelect = document.getElementById('fromMonth');
             var toSelect = document.getElementById('toMonth');
-            var defaultFrom = Math.max(0, fromSelect.options.length - 5);
+
+            // Remove future month options
+            for (var i = fromSelect.options.length - 1; i > maxMonthIdx; i--) {
+                fromSelect.remove(i);
+                toSelect.remove(i);
+            }
+
+            // Hide future month columns permanently
+            document.querySelectorAll('[data-month-idx]').forEach(function(el) {
+                if (parseInt(el.getAttribute('data-month-idx')) > maxMonthIdx) {
+                    el.classList.add('month-hidden');
+                }
+            });
+
+            var defaultFrom = Math.max(0, maxMonthIdx - 4);
             fromSelect.value = defaultFrom;
-            toSelect.value = fromSelect.options.length - 1;
+            toSelect.value = maxMonthIdx;
             applyMonthFilter();
         })();
     </script>