feat(pathanalyzer): jump-to-map from echo rows, message preview in map sidebar

- Each routed echo line in the Messages table gets a map icon that
  switches to the Map view with that message + echo pre-selected and
  its path drawn; the sidebar scrolls the selection into view
- Map sidebar entries show the message content under the sender: one
  truncated line normally, full text when the message is selected;
  sidebar entry markup switched from innerHTML to DOM building so
  network-supplied sender/content strings are never parsed as HTML
- Fix: path drawing (fitBounds) now runs after invalidateSize in the
  same deferred step - drawing immediately after unhiding the map
  container computed bounds against a stale size and left the map at
  world zoom when jumping from the table

Verified live via Playwright: jump selects the right echo (route
chips match the sidebar entry), path draws at zoom 10, previews
truncate on unselected entries and expand on the selected one.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

app/templates/path-analyzer.html

@@ -273,6 +273,22 @@
             color: var(--text-secondary, #6c757d);
         }
 
+        .pa-echo-mapbtn {
+            cursor: pointer;
+            padding: 0 0.3rem;
+            color: var(--text-secondary, #6c757d);
+        }
+
+        .pa-echo-mapbtn:hover {
+            color: #6f42c1;
+        }
+
+        .pa-map-msg-preview {
+            font-size: 0.75rem;
+            color: var(--text-secondary, #6c757d);
+            margin-top: 0.1rem;
+        }
+
         .pa-direct {
             font-size: 0.75rem;
             font-style: italic;