feat(cli): expose replay timing data + times command

[onur-zenos]

The CLI previously surfaced no wall-clock data beyond the raw recorded_utc_timestamp int64, and the footer per-frame time table was unreachable from the command surface entirely.

• new 'times [start] [end]' command: per-frame time table summary (counts, first/last wall clock, durations, median frame step), discontinuity scan (negative or >2x-median created_utc deltas, capped at 100 with anomaly_count/anomalies_truncated), raw gaps/segments, and an optional per-frame slice with deltas
• frame: adds game_time_ticks/_seconds + created_utc_ticks/_iso
• header: adds recorded_utc_iso; info: adds recorded_utc_ticks/_iso
• footer: adds game_time/created_utc/gap/segment counts
• chunks: adds checksum (xxHash64, 0 = not set)
• events: adds derived utc_ticks/_iso (recording start + game_time)
• TimeUtils::FormatUtcTicksIso8601: ISO-8601 sibling of FormatUtcTicks
• TimeUtils::NormalizeUtcToUeTicks: maps unix seconds / unix ms / unix-relative ticks / UE ticks onto one timeline. The writer stamps the header in unix seconds while per-frame created_utc is ticks; every *_iso is derived through normalization, every stored *_ticks passes through raw so deltas stay diagnosable.

Docs in tools/cli/readme.md + CHANGELOG; cli_test_suite.py asserts the new keys, the times slice shape, and times error responses.