add mapbox gl option, gps location, journey reorder + polish

- Mapbox GL provider alongside Leaflet for trip and journey maps (opt-in in
  settings with token, style presets incl. 3D on satellite, quality mode,
  experimental badge).
- GPS "blue dot" with heading cone on mobile; three-state FAB (off / show /
  follow), geodesic accuracy circle, desktop-hidden since browser IP geo is
  too coarse for navigation.
- Marker drift fix: outer wrap no longer carries inline position/transform,
  so mapbox's translate keeps the pin pinned at every zoom and pitch.
- Journey map popup (mapbox-gl): Apple-Maps-style tooltip on marker
  highlight/click showing entry title + location / date subline.
- Journey feed reorder: up/down controls to the left of each entry reorder
  sort_order within a day. Server endpoint, optimistic store update, rollback
  on failure.
- Journey entry editor: desktop modal now centers over the feed column only,
  backdrop still blurs the whole page (map included).
- Scroll-sync guard on journey: marker click locks the sync so smooth-scroll
  can't steer the highlight to a neighbouring entry mid-animation.
- Misc: map top-padding aligned with hero, live/synced badges replaced by a
  compact back-button in the hero, skeleton entries no longer pollute the
  journey map, journey detail no longer shows map on mobile path when
  combined view is active.

server/src/services/journeyService.ts

@@ -598,6 +598,31 @@ export function updateEntry(entryId: number, userId: number, data: Partial<{
   return updated;
 }
 
+// Reorder entries (typically within a single day). Caller passes the new
+// desired order of ids; each entry's sort_order is set to its index in the
+// array. Only entries owned by this journey are accepted.
+export function reorderEntries(journeyId: number, userId: number, orderedIds: number[], sid?: string): boolean {
+  if (!canEdit(journeyId, userId)) return false;
+  if (!orderedIds.length) return true;
+
+  const placeholders = orderedIds.map(() => '?').join(',');
+  const rows = db
+    .prepare(`SELECT id FROM journey_entries WHERE id IN (${placeholders}) AND journey_id = ?`)
+    .all(...orderedIds, journeyId) as { id: number }[];
+  if (rows.length !== orderedIds.length) return false;
+
+  const now = ts();
+  const update = db.prepare('UPDATE journey_entries SET sort_order = ?, updated_at = ? WHERE id = ?');
+  const tx = db.transaction(() => {
+    orderedIds.forEach((id, index) => update.run(index, now, id));
+    db.prepare('UPDATE journeys SET updated_at = ? WHERE id = ?').run(now, journeyId);
+  });
+  tx();
+
+  broadcastJourneyEvent(journeyId, 'journey:entries:reordered', { orderedIds }, sid);
+  return true;
+}
+
 export function deleteEntry(entryId: number, userId: number, sid?: string): boolean {
   const entry = db.prepare('SELECT * FROM journey_entries WHERE id = ?').get(entryId) as JourneyEntry | undefined;
   if (!entry) return false;