fix(map): stabilize notifications during map navigation

Ignore obsolete tile cancellations and update source notices without dismissing their existing toast. Keep notice input above the task ticker and disable swipe removal.

The remaining vertical jitter came from Sonner exit offsets being applied on top of flow positioning. Let flow own geometry and retain opacity transitions; add frame-sampled pan and recovery regression coverage.

src/styles.css

@@ -2445,7 +2445,7 @@ details[open] > summary > .disclosure-accordion-indicator {
   height: min(720px, 80dvh);
   max-width: 760px;
 }
-/* Layout only: keep the shared acrylic material and its shadows unclipped. */
+/* Flow layout owns stack geometry; keep Sonner opacity transitions without its absolute offsets. */
 [data-sonner-toaster].map-notice-stack {
   display: flex;
   flex-direction: column;
@@ -2461,7 +2461,7 @@ details[open] > summary > .disclosure-accordion-indicator {
   bottom: auto;
   flex-shrink: 0;
   height: auto;
-  --y: translateY(0);
+  transform: none;
 }
 [data-sonner-toaster].map-notice-stack [data-sonner-toast][data-visible="false"] {
   display: none;