v0.57.0: re-assert a raw drive's guest-bind (ReassertGuestBinds mount-table fallback)

ReassertGuestBinds mapped durable-id->mount from Observe() only, so a raw enrolled
drive was never found and its in-guest bind wasn't re-asserted after reboot/re-mount
(drive showed "Leválasztva"). Augment the map from the mount table (raw /mnt/<name>
-> device fs-UUID via HostReader), skipping the /mnt/felhom-drives bind; Observe
failure no longer aborts. Completes v0.56.0's raw-drive durability.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

cmd/felhom-agent/main.go

@@ -45,7 +45,7 @@ import (
 
 // version is the agent version. Overridable at build time with
 // -ldflags "-X main.version=<v>"; defaults to the in-repo CHANGELOG version.
-var version = "0.56.0"
+var version = "0.57.0"
 
 // runGuestHook is the PVE pre-start hook body (`felhom-agent guest-hook <vmid> <phase>`). On the
 // pre-start phase it creates placeholder dirs for any absent bind-mount source so the guest always boots