feat: refine itinerary flow and add OSRM connector metrics

documentation/docs/intro/voyage_overview.md

@@ -14,8 +14,9 @@ Voyage is a full-fledged travel companion. With Voyage, you can log your adventu
   - Upload trails and activities to your locations to remember your experiences with detailed maps and stats.
 - **Plan Your Next Trip** 📃: Take the guesswork out of planning your next adventure with an easy-to-use itinerary planner.
   - Itineraries can be created for any number of days and can include multiple destinations.
-  - A timeline-style day view shows ordered stops with numbered markers, compact transportation connector rows (mode, duration, distance), and inline add-place rows per day.
-  - Day-level quick actions include Auto-fill (to populate an empty itinerary from dated records) and an Optimize placeholder for future route optimization.
+  - A timeline-style day view shows ordered stops with numbered markers and compact location cards (no image banners) for a dense overview.
+  - Connector rows between consecutive locations display distance and travel time powered by [OSRM](https://project-osrm.org/) routing (walking if ≤ 20 min, driving otherwise), with automatic haversine fallback when OSRM is unavailable. Self-hosted OSRM instances are supported via the `OSRM_BASE_URL` environment variable. Transportation items appear as separate compact connector rows showing mode, duration, and distance.
+  - Each day has a single `+ Add` control to insert new places, and day-level quick actions include Auto-fill and an Optimize placeholder.
   - Itineraries include many planning features like flight information, notes, checklists, and links to external resources.
   - Itineraries can be shared with friends and family for collaborative planning.
 - **Share Your Experiences** 📸: Share your adventures with friends and family and collaborate on trips together.