feat(config): make trips-for-route running windows configurable

[cotishq]

Summary

This PR resolves #800 by making trips-for-route activity windows configurable instead of hardcoded.

Previously, trips-for-route used fixed values:

• running late window: 30m
• running early window: 10m

Now both are configurable via config.json while preserving the same defaults.

What changed

• Added config fields:
  • running-late-window (seconds, default 1800)
  • running-early-window (seconds, default 600)
• Wired these values through app config into GTFS runtime config (time.Duration).
• Updated trips_for_route_handler to use configured windows with default fallback behavior.
• Added validation to reject negative values.
• Updated docs and config artifacts:
  • README.markdown
  • config.schema.json
  • config.example.json
  • config.docker.example.json
• Updated tests for config loading/validation and handler window behavior.

Backward compatibility

• Existing behavior is unchanged when these fields are not provided.
• Defaults remain:
  • late: 30m
  • early: 10m

Issue

Closes #800

[cotishq]

@Ahmedhossamdev hey can you review this and let me know what changes it still requires before getting merged