Restart stale daemons after agent-cdp upgrades

[V3RON]

agent-cdp now detects when the running daemon was started by a different package version and restarts it automatically before handling daemon-backed commands. Users who upgrade the CLI no longer need to manually kill lingering older daemons to get status, target selection, or capture workflows working reliably again.

Summary

• store the package version in daemon state and use it as the daemon compatibility signal
• restart stale or versionless daemons from the shared bootstrap path, including the status command
• add focused daemon-client tests for reuse, restart-on-mismatch, and restart-on-legacy-state behavior

Backward Compatibility

• Existing commands and flags remain unchanged.
• Default CLI output remains unchanged.
• Older daemon.json files that do not include a version are treated as stale and trigger a restart automatically.
• Daemon lifecycle stays the same from a user perspective, except stale daemons are now refreshed automatically after upgrades.

Risks

• Restarting an incompatible daemon depends on the old process exiting promptly after SIGTERM; if it ignores shutdown, daemon-backed commands will now fail instead of silently talking to stale code.
• status now starts or refreshes the daemon for consistency, which changes its previous behavior of failing when no daemon metadata existed.
• The version source is read from the package manifest at runtime; packaging or distribution changes that move that manifest unexpectedly could affect startup.

Manual testing

• Setup: install or build one version of agent-cdp, start the daemon with agent-cdp start, then update the package to a newer version without manually stopping the daemon.
• Run agent-cdp status.
• Verify the command succeeds and reports status from a freshly started daemon instead of talking to the lingering older process.
• Run another daemon-backed command such as agent-cdp target list.
• Verify it also succeeds without requiring a manual agent-cdp stop first.
• Run agent-cdp stop and verify the daemon still shuts down cleanly.

Closes #6.