fix: prevent TypeError in database General components with null server

Nullable server + guard to avoid TypeError/NPE. Don't terminate the app, terminate the bug.

Changes:
- Made Server property nullable (?Server $server = null) in all 8 database General components
- Added guard clause in mount() to check for null server before accessing it
- Displays user-friendly error message when destination server is not configured
- Prevents crashes in methods like isLogDrainEnabled() and sslCertificates()

Fixed components:
- Mariadb, Dragonfly, Clickhouse, Keydb
- Mysql, Mongodb, Redis, Postgresql

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

app/Livewire/Project/Database/Mongodb/General.php

@@ -18,7 +18,7 @@ class General extends Component
 {
     use AuthorizesRequests;
 
-    public Server $server;
+    public ?Server $server = null;
 
     public StandaloneMongodb $database;
 
@@ -124,6 +124,11 @@ class General extends Component
         try {
             $this->syncData();
             $this->server = data_get($this->database, 'destination.server');
+            if (! $this->server) {
+                $this->dispatch('error', 'Database destination server is not configured.');
+
+                return;
+            }
 
             $existingCert = $this->database->sslCertificates()->first();