The test_older_than tests in both JSON and SQLite prune suites used
hardcoded 2026-04-17 timestamps for the 'new' checkpoint. Once that
date passes, the checkpoint is older than 1 day and gets pruned along
with the 'old' one, causing assert count >= 1 to fail (count=0).
Use 2099-01-01 for the 'new' checkpoint so tests remain stable.
Co-authored-by: Joao Moura <joaomdmoura@gmail.com>
Add three new CLI subcommands to improve checkpoint UX:
- `crewai checkpoint resume [id]` skips the TUI and resumes from the
latest or specified checkpoint directly
- `crewai checkpoint diff <id1> <id2>` compares two checkpoints showing
changes in metadata, inputs, task status, and outputs
- `crewai checkpoint prune --keep N --older-than Xd` removes old
checkpoints from JSON dirs or SQLite databases
Also writes a resume hint to stderr after every checkpoint save so
users discover the command without needing to know it exists.
