feat: validate consecutive stop times with same time

[mackenziereading19]

Summary

Implements #178 by porting the historical Google Python validator check for trips with too many consecutive stop_times.txt rows sharing the same fully specified time.

The validator:

• runs per trip_id using the existing grouped stop-time table architecture;
• reports an INFO notice when a run contains more than five consecutive stop-time records with the same arrival/departure time;
• preserves the historical Python validator semantics for intervening rows with a missing arrival or departure time, which may contribute to a potential run that is later confirmed by a fully specified row;
• emits one notice per qualifying run with tripId, entityCount, and time.

Tests

Added focused regression coverage for:

• exactly five matching stop times: no notice;
• six matching stop times: notice;
• run termination when the time changes;
• qualifying run at end of trip;
• historical missing-time behavior;
• multiple qualifying runs in one trip;
• independent evaluation of different trips.

Focused result: 7 passed.

Full :main:test result locally: 682 passed, 3 failed. The three failures are pre-existing Java 21 / Mockito environment failures (JsonReportSummaryGeneratorTest x2 and VersionResolverTest) and were reproduced independently on untouched baseline 21b27a4ac903bc2bc43d42a89bb3dbb47cc8921d.

Closes #178