feat: Add tap-to-show path popup for mobile devices

Tooltips don't work on touchscreens. Added a popup that appears on
tap/click, shows the full path, and auto-dismisses after 4 seconds.

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

app/static/css/style.css

@@ -1123,8 +1123,27 @@ main {
 
 /* Path info in message meta (incoming messages) */
 .path-info {
-    cursor: help;
+    cursor: pointer;
     border-bottom: 1px dotted currentColor;
+    position: relative;
+}
+
+/* Path popup (mobile-friendly tooltip) */
+.path-popup {
+    position: absolute;
+    bottom: 100%;
+    left: 50%;
+    transform: translateX(-50%);
+    background-color: #333;
+    color: #fff;
+    padding: 0.35rem 0.6rem;
+    border-radius: 0.375rem;
+    font-size: 0.7rem;
+    white-space: nowrap;
+    z-index: 1000;
+    pointer-events: none;
+    margin-bottom: 4px;
+    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.25);
 }
 
 /* =============================================================================

app/static/js/app.js

@@ -721,7 +721,7 @@ function createMessageElement(msg) {
         const shortPath = segments.length > 4
             ? `${segments[0]}\u2192...\u2192${segments[segments.length - 1]}`
             : segments.join('\u2192');
-        metaInfo += ` | <span class="path-info" title="Path: ${fullPath}">Route: ${shortPath}</span>`;
+        metaInfo += ` | <span class="path-info" onclick="showPathPopup(this, '${fullPath}')">Route: ${shortPath}</span>`;
     }
 
     if (msg.is_own) {
@@ -897,6 +897,31 @@ function resendMessage(content) {
     input.focus();
 }
 
+/**
+ * Show path popup on tap (mobile-friendly alternative to tooltip)
+ */
+function showPathPopup(element, fullPath) {
+    // Remove any existing popup
+    const existing = document.querySelector('.path-popup');
+    if (existing) existing.remove();
+
+    const popup = document.createElement('div');
+    popup.className = 'path-popup';
+    popup.textContent = `Path: ${fullPath}`;
+    element.style.position = 'relative';
+    element.appendChild(popup);
+
+    // Auto-dismiss after 4 seconds or on outside tap
+    const dismiss = () => popup.remove();
+    setTimeout(dismiss, 4000);
+    document.addEventListener('click', function handler(e) {
+        if (!element.contains(e.target)) {
+            dismiss();
+            document.removeEventListener('click', handler);
+        }
+    });
+}
+
 /**
  * Load connection status
  */