fix: UTC timezone correction for all JS date parsing across portal

Added global parseUTC() helper in base.html that appends 'Z' to
naive ISO dates from server. Applied to:
- Notification bell (base.html) — formatTimeAgo
- NordaGPT conversation sort (chat.html)
- B2B interest dates (classifieds/view.html)
- Admin forum moderation dates (admin/forum.html)
- Admin AI insights dates (admin/insights.html)

Same fix as conversations.js parseUTC, now available globally.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

templates/admin/forum.html

@@ -1220,7 +1220,7 @@
                         ${r.is_deleted ? '<span style="color: var(--error); font-size: var(--font-size-xs);"> (usunięty)</span>' : ''}
                         <div class="result-preview">${r.content_preview}</div>
                         <div class="result-meta">
-                            ${r.author_name} &bull; ${new Date(r.created_at).toLocaleString('pl-PL')}
+                            ${r.author_name} &bull; ${parseUTC(r.created_at).toLocaleString('pl-PL')}
                             ${r.category_label ? ` &bull; ${r.category_label}` : ''}
                         </div>
                     </div>
@@ -1415,7 +1415,7 @@
                         <a href="${a.url}">${a.title}</a>
                         ${a.is_deleted ? '<span style="color: var(--error);"> (usunięty)</span>' : ''}
                     </div>
-                    <span class="activity-date">${new Date(a.created_at).toLocaleString('pl-PL')}</span>
+                    <span class="activity-date">${parseUTC(a.created_at).toLocaleString('pl-PL')}</span>
                 </div>
             `).join('');
         }

templates/admin/insights.html

@@ -312,7 +312,7 @@ async function loadInsights() {
                         <option value="rejected">Odrzucony</option>
                     </select>
                     <span style="font-size: var(--font-size-xs); color: var(--text-muted);">
-                        ${insight.source_type} | ${insight.created_at ? new Date(insight.created_at).toLocaleDateString('pl-PL') : ''}
+                        ${insight.source_type} | ${insight.created_at ? parseUTC(insight.created_at).toLocaleDateString('pl-PL') : ''}
                     </span>
                 </div>
             </div>

templates/base.html

@@ -858,7 +858,7 @@
 
                 let html = '';
                 data.notifications.forEach(n => {
-                    const timeAgo = formatTimeAgo(new Date(n.created_at));
+                    const timeAgo = formatTimeAgo(parseUTC(n.created_at));
                     const unreadClass = n.is_read ? '' : 'unread';
                     const dotHtml = n.is_read ? '' : '<span class="notification-dot"></span>';
                     const icon = getNotificationIcon(n.notification_type);
@@ -987,6 +987,16 @@
             }
         }
 
+        // Parse server UTC datetime — append Z if no timezone info
+        function parseUTC(dateStr) {
+            if (!dateStr) return new Date();
+            if (typeof dateStr === 'object') return dateStr;
+            if (dateStr.indexOf('Z') === -1 && dateStr.indexOf('+') === -1 && dateStr.indexOf('T') !== -1) {
+                return new Date(dateStr + 'Z');
+            }
+            return new Date(dateStr);
+        }
+
         function formatTimeAgo(date) {
             const now = new Date();
             const diff = now - date;

templates/chat.html

@@ -2265,7 +2265,7 @@ async function togglePin(conversationId) {
             // Re-sort: pinned first, then by updated_at
             conversations.sort((a, b) => {
                 if (a.is_pinned !== b.is_pinned) return b.is_pinned ? 1 : -1;
-                return new Date(b.updated_at) - new Date(a.updated_at);
+                return parseUTC(b.updated_at) - parseUTC(a.updated_at);
             });
             renderConversationsList();
         }

templates/classifieds/view.html

@@ -1078,7 +1078,7 @@ async function showInterestsModal() {
                             ${i.company_name ? `<div class="interest-company">${i.company_name}</div>` : ''}
                             ${i.message ? `<div class="interest-message">"${i.message}"</div>` : ''}
                         </div>
-                        <div class="interest-date">${new Date(i.created_at).toLocaleDateString('pl-PL')}</div>
+                        <div class="interest-date">${parseUTC(i.created_at).toLocaleDateString('pl-PL')}</div>
                     </div>
                 `).join('');
             }