share_menu: drop redundant Host-only sub-header

The HOST block already groups everything that runs on the host
side, so the secondary "Host-only resources" divider between item 4
and item 5 was visual noise — the user reading the menu sees two
HOST sub-titles back to back and has to wonder how items 1-4 differ
from item 5 in scope. They don't; items 1-4 register an external or
local resource as a Proxmox storage, item 5 creates a local shared
directory. Both are host-side actions.

While here, retitle item 5 from "Add Shared Directory on Host" to
"Create Shared Directory on Host" — items 1-4 add an existing
external/local resource, item 5 creates a new one.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

scripts/menus/share_menu.sh

@@ -40,8 +40,7 @@ while true; do
             "3"         "$(translate "Add iSCSI Target as Proxmox Storage")" \
             "4"         "$(translate "Add Local Disk   as Proxmox Storage")" \
             ""          "" \
-            ""  "\Z4─────────────── Host-only resources ──────────────────\Zn" \
-            "5"         "$(translate "Add Shared Directory on Host")" \
+            "5"         "$(translate "Create Shared Directory on Host")" \
             ""          "" \
             ""  "\Z4──────────────────────── LXC ─────────────────────────\Zn" \
             "6"         "$(translate "Configure LXC Mount Points    (Host ↔ Container)")" \