agent v0.50.0: NAS network storage Part A1 (NFS/SMB automount foundation)

Host-side NFS/SMB automount of a bulk-media NAS share under /mnt/felhom-drives/<name>
(propagates into the guest via the existing shared bind), the +100000 uid recipe,
per-share liveness, and add/list/remove local-API endpoints. A NAS is a distinct class
that bypasses the drive enroll/eject/decommission/SMART/watchdog machinery.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HxLA1mZurFq9kt8hneFeCs

internal/config/config.go

@@ -386,6 +386,10 @@ type PrivilegedConfig struct {
 	Install   string `json:"install"`   // default /usr/bin/install
 	Smartctl  string `json:"smartctl"`  // default /usr/sbin/smartctl
 	Lvs       string `json:"lvs"`       // default /usr/sbin/lvs
+
+	// SmbCredsDir is where the agent writes 0600 SMB credentials files for network storage (Part A1).
+	// Out-of-band: never committed, never logged. Default /var/lib/felhom-agent/smb-creds (agent-owned).
+	SmbCredsDir string `json:"smb_creds_dir"`
 }
 
 // Default returns a Config pre-populated with sane defaults.