Add system settings, audit logging, user management, and dark mode fixes

System Settings:
- Add SystemSettings.vue with Zabbix integration, SMTP/email config, SAML SSO settings
- Add Setting model with key-value storage and typed values
- Add settings API with caching

Audit Logging:
- Add AuditLog model tracking user, IP, action, entity changes
- Add comprehensive audit logging to all CRUD operations:
  - Machines, Computers, Equipment, Network devices, VLANs, Subnets
  - Printers, USB devices (including checkout/checkin)
  - Applications, Settings, Users/Roles
- Track old/new values for all field changes
- Mask sensitive values (passwords, tokens) in logs

User Management:
- Add UsersList.vue with full user CRUD
- Add Role management with granular permissions
- Add 41 predefined permissions across 10 categories
- Add users API with roles and permissions endpoints

Reports:
- Add TonerReport.vue for printer supply monitoring

Dark Mode Fixes:
- Fix map position section in PCForm, PrinterForm
- Fix alert-warning in KnowledgeBaseDetail
- All components now use CSS variables for theming

CLI Commands:
- Add flask seed permissions
- Add flask seed settings

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

frontend/src/views/pcs/PCForm.vue

@@ -460,9 +460,11 @@ async function savePC() {
   align-items: center;
   gap: 0.5rem;
   padding: 0.5rem 1rem;
-  background: #e3f2fd;
+  background: var(--bg);
+  border: 1px solid var(--border);
   border-radius: 4px;
   font-family: monospace;
+  color: var(--text);
 }
 
 .map-modal-content {