fix: add validation and escaping for Docker network names

Add strict validation for Docker network names using a regex pattern
that matches Docker's naming rules (alphanumeric start, followed by
alphanumeric, dots, hyphens, underscores).

Changes:
- Add DOCKER_NETWORK_PATTERN to ValidationPatterns with helper methods
- Validate network field in Destination creation and update Livewire components
- Add setNetworkAttribute mutator on StandaloneDocker and SwarmDocker models
- Apply escapeshellarg() to all network field usages in shell commands across
  ApplicationDeploymentJob, DatabaseBackupJob, StartService, Init command,
  proxy helpers, and Destination/Show
- Add comprehensive tests for pattern validation and model mutator

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/Livewire/Destination/New/Docker.php

@@ -5,6 +5,7 @@ namespace App\Livewire\Destination\New;
 use App\Models\Server;
 use App\Models\StandaloneDocker;
 use App\Models\SwarmDocker;
+use App\Support\ValidationPatterns;
 use Illuminate\Foundation\Auth\Access\AuthorizesRequests;
 use Livewire\Attributes\Locked;
 use Livewire\Attributes\Validate;
@@ -24,7 +25,7 @@ class Docker extends Component
     #[Validate(['required', 'string'])]
     public string $name;
 
-    #[Validate(['required', 'string'])]
+    #[Validate(['required', 'string', 'max:255', 'regex:/^[a-zA-Z0-9][a-zA-Z0-9._-]*$/'])]
     public string $network;
 
     #[Validate(['required', 'string'])]