Calculate Travel Time Based on Chained Event Locations, Not Just Home

When a user has multiple events at different locations throughout the day, travel time between consecutive events should be calculated from the previous event's location to the next event's location - not always from home.

Current Behavior: Travel time is calculated independently for each event, always routing from the user's home address. This produces incorrect durations and misplaced time blocks whenever the user is already away from home.

Requested Behavior: Morgen should treat the day's events as a location chain and calculate travel accordingly:

This mirrors how a person actually moves through their day.

Concrete Example:

• 8:30 AM - 1:00 PM: Session in Location A (1:30 hrs from home)

• 1:00 PM: Coffee meeting in Location B (1:30 hrs from home, 20 minutes from location A)

The travel time between these two events should be calculated as Location 1 → Location B (a short drive), not Home → Location B (a much longer route that also produces incorrectly timed and positioned blocks in the calendar).

Why This Matters: For anyone with a multi-stop day, the current behavior makes the travel time feature unreliable - producing wrong durations, blocks placed mid-event, and duplicate time estimates. Chained location routing would make the feature genuinely useful for real-world scheduling.