mount now detects already-unlocked and already-mounted devices, returning
the existing mount point instead of failing. unmount handles already-locked
devices gracefully and skips unmount if not mounted before locking.
Adds IsMounted helper to udisks client. Updates PLAN.md with refined
v1.0.0 milestones.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Go CLI using cobra with mount, unmount, status, and init subcommands.
Unlocks via udisks2 D-Bus (passphrase/keyfile) or cryptsetup (FIDO2/TPM2)
with ordered method fallback. Includes NixOS-specific LD_LIBRARY_PATH
injection for systemd cryptsetup token plugins.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
