Rework entry types: merge hotel into stay, transport with modes, auto-transport

- Type set is now activity/stay/transport/flight/rental/note; hotel, travel
  and immigration are removed with idempotent startup data migrations
  (hotel->stay, travel->transport, immigration->activity with flag prefix)
- Transport entries carry an optional mode (train/bus/ferry/taxi/drive/other)
  that drives the chip/map icon; route stops expose transport_mode
- Creating a stay auto-creates a bridging transport to its neighbouring
  stays unless a transport/flight already covers the gap (one-shot)
- Summary: transports count replaces hotels/travelLegs

public/js/format.js

@@ -6,12 +6,10 @@
 // is roughly most-common-first with Activity as the default for new entries.
 export const ENTRY_TYPES = {
   activity: { label: 'Activity', icon: '📍', color: '#059669' },
-  hotel: { label: 'Hotel', icon: '🏨', color: '#db2777' },
   stay: { label: 'Stay', icon: '🏙️', color: '#f59e0b' },
-  travel: { label: 'Travel', icon: '🚗', color: '#d97706' },
+  transport: { label: 'Transport', icon: '🚆', color: '#d97706' },
   flight: { label: 'Flight', icon: '✈️', color: '#2563eb' },
   rental: { label: 'Rental car', icon: '🚙', color: '#0891b2' },
-  immigration: { label: 'Immigration', icon: '🛂', color: '#7c3aed' },
   note: { label: 'Note', icon: '📝', color: '#64748b' },
 };
 
@@ -20,10 +18,31 @@ export const ENTRY_TYPE_LIST = Object.entries(ENTRY_TYPES).map(([value, meta]) =
   ...meta,
 }));
 
+// Transport entries may carry an optional transport_mode; this is its own
+// select (shown only for type === 'transport'), separate from ENTRY_TYPES.
+export const TRANSPORT_MODES = [
+  { value: 'train', label: 'Train', icon: '🚆' },
+  { value: 'bus', label: 'Bus', icon: '🚌' },
+  { value: 'ferry', label: 'Ferry', icon: '⛴️' },
+  { value: 'taxi', label: 'Taxi', icon: '🚕' },
+  { value: 'drive', label: 'Drive', icon: '🚗' },
+  { value: 'other', label: 'Other', icon: '➡️' },
+];
+
 export function typeInfo(type) {
   return ENTRY_TYPES[type] || { label: type || 'Entry', icon: '•', color: '#64748b' };
 }
 
+// Icon for an entry: a transport entry with a mode shows the mode's icon,
+// otherwise falls back to the type's icon.
+export function entryIcon(entry) {
+  if (entry && entry.type === 'transport' && entry.transport_mode) {
+    const mode = TRANSPORT_MODES.find((m) => m.value === entry.transport_mode);
+    if (mode) return mode.icon;
+  }
+  return typeInfo(entry && entry.type).icon;
+}
+
 // Split modes with the human labels the day-editor select shows.
 export const SPLIT_MODES = [
   { value: 'equal', label: 'Split equally' },