docs: update AGENTS.md with current architecture and fix timeline slider reset

- Rewrite AGENTS.md with directory map, route table, store docs, and
  build/deploy information reflecting current project state
- Fix map timeline slider not resetting to current time when reopening
  the controls panel

src/views/map/MapView.vue

@@ -373,7 +373,10 @@ function handleSliderPointerUp() {
 
 async function toggleTimelineControls() {
   timelineControlsOpen.value = !timelineControlsOpen.value
-  if (!timelineControlsOpen.value) {
+  if (timelineControlsOpen.value) {
+    syncCurrentMinute()
+    selectedMinuteOfDay.value = currentMinuteOfDay.value
+  } else {
     archivePanelOpen.value = false
     sliderDragging.value = false
     if (mapMode.value === 'archive') {