Add rib reconstruction command

[digizeph]

Summary

• add monocle rib to reconstruct final RIB state at arbitrary timestamps
• rebuild each requested rib_ts from the latest prior RIB plus overlapping updates up to the exact target time
• accept timestamps as positional operands instead of repeated --ts flags
• support stdout by default and SQLite export via --sqlite-path
• require --sqlite-path for multi-timestamp runs and write all requested snapshots into one merged SQLite file keyed by rib_ts
• add --country, --origin-asn, --prefix, --as-path, --peer-asn, --collector, --project, and --full-feed-only filters
• abort when no prior RIB exists for a requested collector and timestamp
• update README and changelog for the new command behavior

Examples

monocle rib 2025-09-01T12:00:00Z -c rrc00 -o 13335

monocle rib \
  2025-09-01T12:00:00Z \
  2025-09-01T18:00:00Z \
  --sqlite-path /tmp/rrc00-us.sqlite3 \
  -c rrc00 \
  --country US \
  --full-feed-only