agent v0.33.0: C1 net — pre-start self-heal hook + decommission mp-delete

Pre-start PVE hookscript (internal/guesthook) creates host-root placeholders for
absent bind-mount sources so the guest always boots (fail-closed); decommission
now pct set --delete's the dead mp (GuestBinder.DetachBind) so a missing source
can't brick the next reboot (B3 C1 bug). Non-hollow tests + companions. Installed
+ registered per-guest by the provision back-half. Transitional ahead of the
intermediary-mount re-architecture which makes C1 structural.

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

internal/localapi/disks_test.go

@@ -389,7 +389,11 @@ type fakeGuestAttacher struct {
 		vmid        int
 		slot, where string
 	}
-	reboots []int
+	reboots  []int
+	detaches []struct {
+		vmid int
+		slot string
+	}
 }
 
 func (f *fakeGuestAttacher) AttachBind(_ context.Context, vmid int, mountKey, where string) error {
@@ -403,6 +407,21 @@ func (f *fakeGuestAttacher) AttachBind(_ context.Context, vmid int, mountKey, wh
 }
 func (f *fakeGuestAttacher) count() int { f.mu.Lock(); defer f.mu.Unlock(); return len(f.calls) }
 
+func (f *fakeGuestAttacher) DetachBind(_ context.Context, vmid int, mountKey string) error {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	f.detaches = append(f.detaches, struct {
+		vmid int
+		slot string
+	}{vmid, mountKey})
+	return nil
+}
+func (f *fakeGuestAttacher) detachCount() int {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	return len(f.detaches)
+}
+
 func (f *fakeGuestAttacher) RebootGuest(_ context.Context, vmid int) error {
 	f.mu.Lock()
 	defer f.mu.Unlock()