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/api/client.js

@@ -204,6 +204,8 @@ export const collabApi = {
   createNote: (tripId, data) => apiClient.post(`/trips/${tripId}/collab/notes`, data).then(r => r.data),
   updateNote: (tripId, id, data) => apiClient.put(`/trips/${tripId}/collab/notes/${id}`, data).then(r => r.data),
   deleteNote: (tripId, id) => apiClient.delete(`/trips/${tripId}/collab/notes/${id}`).then(r => r.data),
+  uploadNoteFile: (tripId, noteId, formData) => apiClient.post(`/trips/${tripId}/collab/notes/${noteId}/files`, formData, { headers: { 'Content-Type': 'multipart/form-data' } }).then(r => r.data),
+  deleteNoteFile: (tripId, noteId, fileId) => apiClient.delete(`/trips/${tripId}/collab/notes/${noteId}/files/${fileId}`).then(r => r.data),
   // Polls
   getPolls: (tripId) => apiClient.get(`/trips/${tripId}/collab/polls`).then(r => r.data),
   createPoll: (tripId, data) => apiClient.post(`/trips/${tripId}/collab/polls`, data).then(r => r.data),
@@ -214,6 +216,8 @@ export const collabApi = {
   getMessages: (tripId, before) => apiClient.get(`/trips/${tripId}/collab/messages${before ? `?before=${before}` : ''}`).then(r => r.data),
   sendMessage: (tripId, data) => apiClient.post(`/trips/${tripId}/collab/messages`, data).then(r => r.data),
   deleteMessage: (tripId, id) => apiClient.delete(`/trips/${tripId}/collab/messages/${id}`).then(r => r.data),
+  reactMessage: (tripId, id, emoji) => apiClient.post(`/trips/${tripId}/collab/messages/${id}/react`, { emoji }).then(r => r.data),
+  linkPreview: (tripId, url) => apiClient.get(`/trips/${tripId}/collab/link-preview?url=${encodeURIComponent(url)}`).then(r => r.data),
 }
 
 export const backupApi = {