fix(server): share SSH username validation

Centralize SSH username rules and sanitization so dotted usernames are
accepted consistently across API, onboarding, and Livewire server forms.

app/Http/Controllers/Api/ServersController.php

@@ -13,6 +13,7 @@ use App\Models\PrivateKey;
 use App\Models\Project;
 use App\Models\Server as ModelsServer;
 use App\Rules\ValidServerIp;
+use App\Support\ValidationPatterns;
 use Illuminate\Http\JsonResponse;
 use Illuminate\Http\Request;
 use OpenApi\Attributes as OA;
@@ -487,7 +488,7 @@ class ServersController extends Controller
             'ip' => ['string', 'required', new ValidServerIp],
             'port' => 'integer|nullable|between:1,65535',
             'private_key_uuid' => 'string|required',
-            'user' => ['string', 'nullable', 'regex:/^[a-zA-Z0-9._-]+$/'],
+            'user' => ValidationPatterns::serverUsernameRules(required: false),
             'is_build_server' => 'boolean|nullable',
             'instant_validate' => 'boolean|nullable',
             'proxy_type' => 'string|nullable',
@@ -666,7 +667,7 @@ class ServersController extends Controller
             'ip' => ['string', 'nullable', new ValidServerIp],
             'port' => 'integer|nullable|between:1,65535',
             'private_key_uuid' => 'string|nullable',
-            'user' => ['string', 'nullable', 'regex:/^[a-zA-Z0-9._-]+$/'],
+            'user' => ValidationPatterns::serverUsernameRules(required: false),
             'is_build_server' => 'boolean|nullable',
             'instant_validate' => 'boolean|nullable',
             'proxy_type' => 'string|nullable',

app/Livewire/Boarding/Index.php

@@ -8,6 +8,7 @@ use App\Models\Project;
 use App\Models\Server;
 use App\Models\Team;
 use App\Services\ConfigurationRepository;
+use App\Support\ValidationPatterns;
 use Illuminate\Support\Collection;
 use Livewire\Attributes\Url;
 use Livewire\Component;
@@ -278,7 +279,7 @@ class Index extends Component
             'remoteServerName' => 'required|string',
             'remoteServerHost' => 'required|string',
             'remoteServerPort' => 'required|integer',
-            'remoteServerUser' => 'required|string|regex:/^[a-zA-Z0-9._-]+$/',
+            'remoteServerUser' => ValidationPatterns::serverUsernameRules(),
         ]);
 
         $this->privateKey = formatPrivateKey($this->privateKey);
@@ -467,7 +468,7 @@ class Index extends Component
     {
         $this->validate([
             'remoteServerPort' => 'required|integer|min:1|max:65535',
-            'remoteServerUser' => 'required|string|regex:/^[a-zA-Z0-9._-]+$/',
+            'remoteServerUser' => ValidationPatterns::serverUsernameRules(),
         ]);
 
         $this->createdServer->update([

app/Livewire/Server/New/ByIp.php

@@ -57,7 +57,7 @@ class ByIp extends Component
             'name' => ValidationPatterns::nameRules(),
             'description' => ValidationPatterns::descriptionRules(),
             'ip' => ['required', 'string', new ValidServerIp],
-            'user' => ['required', 'string', 'regex:/^[a-zA-Z0-9._-]+$/'],
+            'user' => ValidationPatterns::serverUsernameRules(),
             'port' => 'required|integer|between:1,65535',
             'is_build_server' => 'required|boolean',
         ];
@@ -75,6 +75,7 @@ class ByIp extends Component
             'ip.string' => 'The IP Address/Domain must be a string.',
             'user.required' => 'The User field is required.',
             'user.string' => 'The User field must be a string.',
+            ...ValidationPatterns::serverUsernameMessages(),
             'port.required' => 'The Port field is required.',
             'port.integer' => 'The Port field must be an integer.',
             'port.between' => 'The Port field must be between 1 and 65535.',

app/Livewire/Server/Show.php

@@ -110,7 +110,7 @@ class Show extends Component
             'name' => ValidationPatterns::nameRules(),
             'description' => ValidationPatterns::descriptionRules(),
             'ip' => ['required', new ValidServerIp],
-            'user' => ['required', 'regex:/^[a-zA-Z0-9._-]+$/'],
+            'user' => ValidationPatterns::serverUsernameRules(),
             'port' => 'required|integer|between:1,65535',
             'connectionTimeout' => 'required|integer|min:1|max:300',
             'validationLogs' => 'nullable',
@@ -140,6 +140,7 @@ class Show extends Component
             [
                 'ip.required' => 'The IP Address field is required.',
                 'user.required' => 'The User field is required.',
+                ...ValidationPatterns::serverUsernameMessages(),
                 'port.required' => 'The Port field is required.',
                 'connectionTimeout.required' => 'The SSH Connection Timeout field is required.',
                 'connectionTimeout.integer' => 'The SSH Connection Timeout must be an integer.',

app/Models/Server.php

@@ -17,6 +17,7 @@ use App\Livewire\Server\Proxy;
 use App\Notifications\Server\Reachable;
 use App\Notifications\Server\Unreachable;
 use App\Services\ConfigurationRepository;
+use App\Support\ValidationPatterns;
 use App\Traits\ClearsGlobalSearchCache;
 use App\Traits\HasMetrics;
 use App\Traits\HasSafeStringAttribute;
@@ -945,10 +946,10 @@ $schema://$host {
     {
         return Attribute::make(
             get: function ($value) {
-                return preg_replace('/[^A-Za-z0-9.\-_]/', '', $value);
+                return preg_replace(ValidationPatterns::INVALID_SERVER_USERNAME_CHARACTERS_PATTERN, '', $value);
             },
             set: function ($value) {
-                return preg_replace('/[^A-Za-z0-9.\-_]/', '', $value);
+                return preg_replace(ValidationPatterns::INVALID_SERVER_USERNAME_CHARACTERS_PATTERN, '', $value);
             }
         );
     }

app/Support/ValidationPatterns.php

@@ -35,6 +35,17 @@ class ValidationPatterns
      */
     public const DOCKER_TARGET_PATTERN = '/^[a-zA-Z0-9][a-zA-Z0-9._-]*$/';
 
+    /**
+     * Pattern for SSH usernames.
+     * Allows alphanumeric characters, dots, hyphens, and underscores.
+     */
+    public const SERVER_USERNAME_PATTERN = '/^[a-zA-Z0-9._-]+$/';
+
+    /**
+     * Pattern for removing characters not allowed in SSH usernames.
+     */
+    public const INVALID_SERVER_USERNAME_CHARACTERS_PATTERN = '/[^A-Za-z0-9.\-_]/';
+
     /**
      * Token-aware pattern for shell-safe command strings (docker compose commands, docker run options).
      *
@@ -124,6 +135,28 @@ class ValidationPatterns
         return $rules;
     }
 
+    /**
+     * Get validation rules for SSH username fields.
+     */
+    public static function serverUsernameRules(bool $required = true): array
+    {
+        return [
+            $required ? 'required' : 'nullable',
+            'string',
+            'regex:'.self::SERVER_USERNAME_PATTERN,
+        ];
+    }
+
+    /**
+     * Get validation messages for SSH username fields.
+     */
+    public static function serverUsernameMessages(string $field = 'user', string $label = 'User'): array
+    {
+        return [
+            "{$field}.regex" => "The {$label} may only contain letters, numbers, dots, hyphens, and underscores.",
+        ];
+    }
+
     /**
      * Get validation messages for database identifier fields.
      */