Fix break ordering after shipment delivery

[william-xue]

Issue

Fixes #1345.

Root cause

When evaluating a pickup while a break is pending, TWRoute::order_choice returned early as soon as pickup -> break -> delivery missed the delivery deadline. That skipped the pickup-specific fallback which also evaluates pickup -> delivery -> break, so a feasible shipment was rejected.

Tasks

• Continue pickup-specific ordering checks when the immediate break placement misses the next task
• Add a regression instance for the reported delivery and break windows
• Verify the route has no unassigned tasks and orders pickup, delivery, then break

Validation

• make -j2 USE_ROUTING=false
• Regression before fix: 0 routes, 2 unassigned tasks
• Regression after fix: 1 route, 0 unassigned tasks; delivery arrival 39900, break arrival 40800, route end 43500
• Existing docs/example_2.json output matches docs/example_2_sol.json
• git diff --check

[william-xue]

Closing this for now — not because the fix is invalid, but because there is no review signal on it.

Summary of what is on the branch: it restores feasible pickup → delivery → break ordering in a one-vehicle PDPTW when the delivery and break windows are disjoint. Regression on the bundled instance: before 0 routes / 2 unassigned, after 1 route / 0 unassigned, objective cost/duration 5,400, with precedence, time-window and vehicle-horizon invariants satisfied. Both Sonar checks pass; the Actions workflow stays in action_required because it needs fork-workflow approval upstream.

The branch remains at william-xue:vroom (fix/break-ordering-shipment) with the regression test, so it is a one-command revive. I am happy to reopen, rebase and adjust to whatever direction you prefer as soon as there is interest — I just do not want to keep it sitting in the queue looking like an active proposal.