Change 32806
Add snapshot-based live checkpoint to live_checkpoint.sh / backup_functions.sh.
Rotate journal -> consistent snapshot of P4ROOT via 'p4d -c' -> dump checkpoint
from the snapshot (offline), shrinking the live-DB lock from the whole checkpoint
to the brief snapshot. Methods auto-detected: reflink (local CoW) -> aws/azure/gcp
volume snapshot -> fall back to in-place checkpoint(). Includes multi-agent-review
fixes (parallel-mode skip, half-written guard, method validation, cloud cleanup
subshell leak, non-fatal rotation). Config via SNAPSHOT_* vars (documented in p4_vars).
Rotate journal -> consistent snapshot of P4ROOT via 'p4d -c' -> dump checkpoint
from the snapshot (offline), shrinking the live-DB lock from the whole checkpoint
to the brief snapshot. Methods auto-detected: reflink (local CoW) -> aws/azure/gcp
volume snapshot -> fall back to in-place checkpoint(). Includes multi-agent-review
fixes (parallel-mode skip, half-written guard, method validation, cloud cleanup
subshell leak, non-fatal rotation). Config via SNAPSHOT_* vars (documented in p4_vars).