docs(grimmory): fix IP assignment — PVE static config, not DHCP reservation

All LXCs use ip=<addr>/24 in pve net0 config directly. No Fritz!Box
lease needed. Updated container doc and migration runbook accordingly.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

containers/130-grimmory.md

@@ -5,7 +5,7 @@ Self-hosted digital library (eBooks, comics, audiobooks). Community fork/success
 ## At a glance
 
 - **Hostname:** `grimmory`
-- **IP:** `192.168.8.213` (static DHCP reservation)
+- **IP:** `192.168.8.213` (static, set in PVE `net0` config — same pattern as all other LXCs)
 - **Privilege:** privileged (UID = host UID for `/mnt/library` media GID)
 - **Resources:** 1 core / 2 GiB RAM / 16 GiB rootfs (Debian 13)
 - **Mounts:** `/mnt/library`