Trip dock: default date to vehicle's last-active day; UI review fixes

- Plain click defaults the trip date to the vehicle's most recent fix day (no more empty 'today' at night); manual date picks are respected.

- Animated trip path/marker now use the trip's palette colour (matched the card).

- Filter dropdown skips no-op rebuilds on the 15s refresh and won't rebuild under an open popover.

- applyClientFilter: drop redundant length>0 guard.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

web/fleet-core.js

@@ -553,6 +553,7 @@ function _buildMultiSelect(root, { label, plural, showSwatch }) {
 
   const listeners = [];
   let options = []; // [{value, color?}]
+  let lastSig = '';  // skip no-op rebuilds on the 15s live refresh
 
   const updateLabel = () => {
     const checked = [...optsRoot.querySelectorAll('input:checked')];
@@ -597,6 +598,12 @@ function _buildMultiSelect(root, { label, plural, showSwatch }) {
 
   return {
     setOptions(opts) {
+      // Skip the DOM rebuild when the option set is unchanged (the 15s live
+      // refresh re-sends the same list) or while the popover is open — both
+      // would otherwise flicker the list / disrupt a mid-selection.
+      const sig = opts.map(o => `${o.value}:${o.color || ''}`).join('|');
+      if (sig === lastSig || !pop.hasAttribute('hidden')) return;
+      lastSig = sig;
       options = opts;
       // Preserve current selections by value when re-rendering
       const prevChecked = new Set(
@@ -635,10 +642,10 @@ function _buildMultiSelect(root, { label, plural, showSwatch }) {
 export function applyClientFilter(map, { costCentres = [], cities = [] } = {}) {
   const layers = ['vehicles-circle', 'vehicles-arrow', 'vehicles-label'];
   const conds = [];
-  if (costCentres.length > 0 && costCentres.length > 1) {
+  if (costCentres.length > 1) {
     conds.push(['in', ['get', 'cost_centre'], ['literal', costCentres]]);
   }
-  if (cities.length > 0 && cities.length > 1) {
+  if (cities.length > 1) {
     conds.push(['in', ['get', 'assigned_city'], ['literal', cities]]);
   }
   const filter = conds.length === 0 ? null
@@ -703,6 +710,9 @@ let _tripAnimRAF = null;
 // vehicleId → { plate, driver, color, payload | null }
 const _selection = new Map();
 let _currentDate = null;
+// Once the user picks a date in the dock we stop auto-jumping to a vehicle's
+// last-active day on click, so date-browsing isn't fought by every click.
+let _dateUserPicked = false;
 
 function _nextColor() {
   const used = new Set([..._selection.values()].map(v => v.color));
@@ -725,6 +735,7 @@ export function initTripPanel(map, panelRoot) {
 
   els.close.addEventListener('click', () => _closeTripPanel(map, panelRoot, els));
   els.date.addEventListener('change', async () => {
+    _dateUserPicked = true;
     _currentDate = els.date.value;
     // Re-fetch every currently-selected vehicle for the new date.
     for (const vid of [..._selection.keys()]) {
@@ -749,7 +760,15 @@ export function initTripPanel(map, panelRoot) {
     const driver = f.properties.driver_name || '';
     const multi  = e.originalEvent.metaKey || e.originalEvent.ctrlKey || e.originalEvent.shiftKey;
 
-    if (!els.date.value) els.date.value = _todayEat();
+    // Plain click → jump to the vehicle's most recent active day (its last
+    // fix), so the dock never opens on an empty "today" before the fleet has
+    // moved. Once the user has chosen a date, respect it. Multi-click keeps
+    // the current date so compared vehicles share one day.
+    if (!multi && !_dateUserPicked) {
+      els.date.value = _eatDate(f.properties.occurred_at);
+    } else if (!els.date.value) {
+      els.date.value = _todayEat();
+    }
     _currentDate = els.date.value;
     panelRoot.classList.add('open');
     panelRoot.setAttribute('aria-hidden', 'false');
@@ -1048,6 +1067,9 @@ function _showAndAnimateTrip(map, trip) {
   _clearSingleTripLayers(map);
   if (!trip.path || !trip.path.coordinates || trip.path.coordinates.length < 2) return;
   const coords = trip.path.coordinates;
+  // Match the trip card's palette colour so the animated route reads as the
+  // same trip the user clicked.
+  const color = _tripColor(trip.trip_id);
 
   map.addSource(TRIP_PATH_SOURCE, { type: 'geojson', data: trip.path });
   map.addLayer({
@@ -1056,7 +1078,7 @@ function _showAndAnimateTrip(map, trip) {
     source: TRIP_PATH_SOURCE,
     layout: { 'line-join': 'round', 'line-cap': 'round' },
     paint: {
-      'line-color': '#10b981',
+      'line-color': color,
       'line-width': ['interpolate', ['linear'], ['zoom'], 8, 2, 14, 4, 17, 6],
       'line-opacity': 0.85,
     },
@@ -1073,7 +1095,7 @@ function _showAndAnimateTrip(map, trip) {
     paint: {
       'circle-radius': ['interpolate', ['linear'], ['zoom'], 8, 4, 14, 8, 17, 12],
       'circle-color': '#ffffff',
-      'circle-stroke-color': '#10b981',
+      'circle-stroke-color': color,
       'circle-stroke-width': 3,
     },
   });
@@ -1161,6 +1183,14 @@ function _todayEat() {
   return eat.toISOString().slice(0, 10);
 }
 
+// EAT (UTC+3) calendar date of a UTC ISO timestamp, as YYYY-MM-DD. Falls back
+// to today when the timestamp is missing/unparseable.
+function _eatDate(iso) {
+  const d = iso ? new Date(iso) : new Date();
+  if (Number.isNaN(d.getTime())) return _todayEat();
+  return new Date(d.getTime() + 3 * 3600 * 1000).toISOString().slice(0, 10);
+}
+
 function _formatTimeOnly(iso) {
   if (!iso) return '—';
   const d = new Date(iso);