feat(ui): improve delivery time handling

[Gill87]

Summary

• Vehicle add/edit departure time now defaults blank minutes to 00 after a valid hour is entered, allowing common on-the-hour departures to save without an extra manual minute entry.
• Confirmed address cards now distinguish one-sided delivery windows: start-only windows show From <time>, end-only windows show By <time>, full ranges and empty windows keep their prior display.

Motivation

• Issue feat: Add "00" in the minute slot when a number is entered in the hour slot (vehicle creation) #209 reports that users often type only an hour for vehicle departure time, then hit validation because the separate minutes field stays blank.
• Issue feat: Distinguish Start and End Delivery Times #211 reports that confirmed delivery cards displayed start-only and end-only windows as identical bare times, making the schedule ambiguous while scanning the route setup list.
• These UI improvements reduce form friction and make locked delivery details clearer before optimization.

Changes

• Frontend: added vehicle departure-time helper logic that fills blank minutes with 00 only for valid hours from 1 through 12.
• Frontend: tracks whether 00 was generated by the UI so user-entered minutes, including a deliberate 00, are not overwritten.
• Frontend: added a shared locked delivery-time formatter and reused it in both desktop and mobile locked address-card views.
• Frontend tests: added focused Vitest coverage for departure minute defaulting, generated-minute clearing, user-entered minute preservation, and locked delivery-window labels.
• Backend, infrastructure, mobile app, and documentation behavior are unchanged by this PR.

Validation

Frontend

• npm --prefix app/ui test -- deliveryHelpers.test.ts — passed: 1 test file, 10 tests.
• npm --prefix app/ui run typecheck — passed.
• npm --prefix app/ui test — passed: 24 test files, 122 tests.
• npm --prefix app/ui run lint — skipped locally; CI will run the full lint gate for the branch.
• npm --prefix app/ui run format:check — skipped locally; CI will run the formatting gate for the branch.
• npm --prefix app/ui run build — skipped locally; CI will run the production build gate for the branch.

Other Checks

• npm --prefix app/mobile run lint — skipped locally because the mobile app is outside this UI change.
• npm --prefix app/mobile run typecheck — skipped locally because the mobile app is outside this UI change.
• cmake --preset dev — skipped locally because backend code is outside this UI change.
• .github/scripts/check-backend-static.sh build/dev — skipped locally because backend code is outside this UI change.
• cmake --build --preset dev --parallel — skipped locally because backend code is outside this UI change.
• ctest --preset dev --output-on-failure --no-tests=error -LE 'e2e|docker' — skipped locally because backend code is outside this UI change.

Risk

• Low UI risk: both changes are limited to edit-page time handling and confirmed address-card display text.
• The main departure-time risk is accidentally overwriting custom minutes; generated-minute state and focused tests cover user-entered minute preservation.
• The main address-card risk is inconsistent desktop/mobile wording; both locked views call the same formatter and share unit coverage.
• Saved data, validation constraints, solver payloads, and backend behavior are not changed.

Rollout and Recovery

• Rollout follows the normal frontend deployment path for the Next.js UI.
• Recovery is a small revert of the departure-time helper, locked delivery-window formatter, and their focused tests if unexpected editing or display behavior appears.
• Data migration, feature flag setup, and backfill work are not required.

High-Signal PR Checklist

• The summary states the user-visible outcome.
• The motivation explains why the changes are needed.
• The change list separates frontend work from unaffected areas.
• Validation includes exact commands run and checks intentionally left to CI.
• Risks and rollback steps are called out.
• UI behavior is described in text and covered by focused unit tests.