ansible: add reboot playbook and short hostname support

- Add reboot.yml playbook with rolling reboot (serial: 1)
  - Uses systemd reboot.target for NixOS compatibility
  - Waits for each host to come back before proceeding
- Update dynamic inventory to use short hostnames
  - ansible_host set to FQDN for connections
  - Allows -l testvm01 instead of -l testvm01.home.2rjus.net
- Update static.yml to match short hostname convention

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

ansible/inventory/dynamic_flake.py

@@ -102,28 +102,32 @@ def build_inventory(hosts_data: dict) -> dict:
 
         fqdn = f"{hostname}.{domain}"
 
+        # Use short hostname as inventory name, FQDN for connection
+        inventory_name = hostname
+
         # Add to flake_hosts group
-        inventory["flake_hosts"]["hosts"].append(fqdn)
+        inventory["flake_hosts"]["hosts"].append(inventory_name)
 
         # Add host variables
-        inventory["_meta"]["hostvars"][fqdn] = {
+        inventory["_meta"]["hostvars"][inventory_name] = {
+            "ansible_host": fqdn,  # Connect using FQDN
+            "fqdn": fqdn,
             "tier": tier,
             "role": role,
-            "short_hostname": hostname,
         }
 
         # Group by tier
         tier_group = f"tier_{sanitize_group_name(tier)}"
         if tier_group not in tier_groups:
             tier_groups[tier_group] = []
-        tier_groups[tier_group].append(fqdn)
+        tier_groups[tier_group].append(inventory_name)
 
         # Group by role (if set)
         if role:
             role_group = f"role_{sanitize_group_name(role)}"
             if role_group not in role_groups:
                 role_groups[role_group] = []
-            role_groups[role_group].append(fqdn)
+            role_groups[role_group].append(inventory_name)
 
     # Add tier groups to inventory
     for group_name, hosts in tier_groups.items():