v2.6.0 — Collab overhaul, route travel times, chat & notes redesign

## Collab — Complete Redesign
- iMessage-style live chat with blue bubbles, grouped messages, date separators
- Emoji reactions via right-click (desktop) or double-tap (mobile)
- Twemoji (Apple-style) emoji picker with categories
- Link previews with OG image/title/description
- Soft-delete messages with "deleted a message" placeholder
- Message reactions with real-time WebSocket sync
- Chat timestamps respect 12h/24h setting and timezone

## Collab Notes
- Redesigned note cards with colored header bar (booking-card style)
- 2-column grid layout (desktop), 1-column (mobile)
- Category settings modal for managing categories with colors
- File/image attachments on notes with mini-preview thumbnails
- Website links with OG image preview on note cards
- File preview portal (lightbox for images, inline viewer for PDF/TXT)
- Note files appear in Files tab with "From Collab Notes" badge
- Pin highlighting with tinted background
- Author avatar chip in header bar with custom tooltip

## Collab Polls
- Complete rewrite — clean Apple-style poll cards
- Animated progress bars with vote percentages
- Blue check circles for own votes, voter avatars
- Create poll modal with multi-choice toggle
- Active/closed poll sections
- Custom tooltips on voter chips

## What's Next Widget
- New widget showing upcoming trip activities
- Time display with "until" separator
- Participant chips per activity
- Day grouping (Today, Tomorrow, dates)
- Respects 12h/24h and locale settings

## Route Travel Times
- Auto-calculated walking + driving times via OSRM (free, no API key)
- Floating badge on each route segment between places
- Walking person icon + car icon with times
- Hides when zoomed out (< zoom 16)
- Toggle in Settings > Display to enable/disable

## Other Improvements
- Collab addon enabled by default for new installations
- Coming Soon removed from Collab in admin settings
- Tab state persisted across page reloads (sessionStorage)
- Day sidebar expanded/collapsed state persisted
- File preview with extension badges (PDF, TXT, etc.) in Files tab
- Collab Notes filter tab in Files
- Reservations section in Day Detail view
- Dark mode fix for invite button text color
- Chat scroll hidden (no visible scrollbar)
- Mobile: tab icons removed for space, touch-friendly UI
- Fixed 6 backend data structure bugs in Collab (polls, chat, notes)
- Soft-delete for chat messages (persists in history)
- Message reactions table (migration 28)
- Note attachments via trip_files with note_id (migration 30)

## Database Migrations
- Migration 27: budget_item_members table
- Migration 28: collab_message_reactions table
- Migration 29: soft-delete column on collab_messages
- Migration 30: note_id on trip_files, website on collab_notes

client/src/components/Planner/DayPlanSidebar.jsx

@@ -92,7 +92,13 @@ export default function DayPlanSidebar({
 
   const dayNotes = tripStore.dayNotes || {}
 
-  const [expandedDays, setExpandedDays] = useState(() => new Set(days.map(d => d.id)))
+  const [expandedDays, setExpandedDays] = useState(() => {
+    try {
+      const saved = sessionStorage.getItem(`day-expanded-${tripId}`)
+      if (saved) return new Set(JSON.parse(saved))
+    } catch {}
+    return new Set(days.map(d => d.id))
+  })
   const [editingDayId, setEditingDayId] = useState(null)
   const [editTitle, setEditTitle] = useState('')
   const [isCalculating, setIsCalculating] = useState(false)
@@ -128,9 +134,20 @@ export default function DayPlanSidebar({
     return { placeId, assignmentId: '', noteId: '', fromDayId: 0 }
   }
 
+  // Only auto-expand genuinely new days (not on initial load from storage)
+  const prevDayCount = React.useRef(days.length)
   useEffect(() => {
-    setExpandedDays(prev => new Set([...prev, ...days.map(d => d.id)]))
-  }, [days.length])
+    if (days.length > prevDayCount.current) {
+      // New days added — expand only those
+      setExpandedDays(prev => {
+        const n = new Set(prev)
+        days.forEach(d => { if (!prev.has(d.id)) n.add(d.id) })
+        try { sessionStorage.setItem(`day-expanded-${tripId}`, JSON.stringify([...n])) } catch {}
+        return n
+      })
+    }
+    prevDayCount.current = days.length
+  }, [days.length, tripId])
 
   useEffect(() => {
     if (editingDayId && inputRef.current) inputRef.current.focus()
@@ -154,6 +171,7 @@ export default function DayPlanSidebar({
     setExpandedDays(prev => {
       const n = new Set(prev)
       n.has(dayId) ? n.delete(dayId) : n.add(dayId)
+      try { sessionStorage.setItem(`day-expanded-${tripId}`, JSON.stringify([...n])) } catch {}
       return n
     })
   }