fix: OS template type matching for LXC/KVM nodes

- Add is_lxc column to ext_proxmox_oses for tracking template type
- OS model now has vmType() helper returning 'lxc' or 'qemu'
- Install uses OS template's type for clone API path (not node type)
- createServer validates OS type matches node type before provisioning
- calculateNode filters nodes by LXC/KVM type based on selected OS
- Reinstall OS list filtered to only show matching template types
- Admin location OS repeater now has LXC Template checkbox

extensions/Servers/Proxmox/database/migrations/2026_03_02_000002_add_is_lxc_to_ext_proxmox_oses_table.php

@@ -0,0 +1,22 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    public function up(): void
+    {
+        Schema::table('ext_proxmox_oses', function (Blueprint $table) {
+            $table->boolean('is_lxc')->default(false)->after('location_id');
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::table('ext_proxmox_oses', function (Blueprint $table) {
+            $table->dropColumn('is_lxc');
+        });
+    }
+};