v0.1.14

Duplicate-send protection

• Add process-safe sendguard outbound-send claims with a flock-protected, pruned ledger and optional remote history checks.
• Store only a SHA-256 digest rather than account, destination, or body text.
• Preserve uncertain attempts as unverified, with explicit duplicate overrides for intentional repeated sends.
• Map duplicate_send to CLI exit 4 and HTTP 409 across operation surfaces.
• Bound claim-finalization locks, fsync the ledger parent directory, and recover safely from an unterminated trailing ledger record.
• Use golang.org/x/text v0.39.0 to address GO-2026-5970.