fix: route back-button and map popup flicker (#1.13.5)

- Replace two fixed-destination back-buttons on the route page with a
  single arrow_back button using window.history.back(), so navigation
  always returns to the calling screen (Messages or Archive).

- Guard setIcon() and setPopupContent() in applyDevice/applyContacts
  behind isPopupOpen() to prevent popup flickering on the 500 ms
  update tick.

- Set fadeAnimation: false and markerZoomAnimation: false on both
  Leaflet map instances (main map and route map) to eliminate popup
  flash on first click, particularly noticeable on Raspberry Pi.

meshcore_gui/gui/route_page.py

@@ -143,12 +143,8 @@ class RoutePage:
         with ui.header().classes('items-center px-4 py-2 shadow-md'):
             ui.button(
                 icon='arrow_back',
-                on_click=lambda: ui.navigate.to('/'),
-            ).props('flat round dense color=white').tooltip('Back to Dashboard')
-            ui.button(
-                icon='history',
-                on_click=lambda: ui.navigate.to('/archive'),
-            ).props('flat round dense color=white').tooltip('Back to Archive')
+                on_click=lambda: ui.run_javascript('window.history.back()'),
+            ).props('flat round dense color=white').tooltip('Back')
             ui.label('🗺️ MeshCore Route').classes(
                 'text-lg font-bold domca-header-text'
             ).style("font-family: 'JetBrains Mono', monospace")