fix(engine-b): apply plan CPU/RAM; idempotent backup + monitoring registration

- ConfigureCloudInit sets cores/memory from the plan (not the template default).
- RegisterBackup uses a deterministic Proxmox job id (ignore-exists) + firstOrCreate.
- RegisterMonitoring is idempotent by URL + firstOrCreate — no duplicate schedules
  or monitors after a crash/retry.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

app/Provisioning/Steps/Customer/ConfigureCloudInit.php

@@ -32,6 +32,8 @@ class ConfigureCloudInit extends CustomerStep
             'ipconfig0' => 'ip=dhcp',
             'ciuser' => 'clupilot',
             'nameserver' => '1.1.1.1',
+            'cores' => $instance->cores,      // apply the plan's CPU/RAM, not the template's
+            'memory' => $instance->ram_mb,
         ]);
         // Absolute target (not '+…') so a retry can't grow the disk twice.
         $pve->resizeDisk($node, $vmid, 'scsi0', $instance->disk_gb.'G');

app/Provisioning/Steps/Customer/RegisterBackup.php

@@ -34,11 +34,12 @@ class RegisterBackup extends CustomerStep
             ->createBackupJob((string) $run->context('node'), (int) $instance->vmid, $schedule);
 
         $this->recordResource($run, $instance->host, 'backup_job_id', $jobId);
-        $instance->backups()->create([
-            'external_job_id' => $jobId,
-            'schedule' => $schedule,
-            'status' => 'scheduled',
-        ]);
+        // firstOrCreate keyed on the deterministic job id → no duplicate row if a
+        // crash re-runs this step before the breadcrumb was recorded.
+        $instance->backups()->firstOrCreate(
+            ['external_job_id' => $jobId],
+            ['schedule' => $schedule, 'status' => 'scheduled'],
+        );
 
         return StepResult::advance();
     }

app/Provisioning/Steps/Customer/RegisterMonitoring.php

@@ -33,11 +33,10 @@ class RegisterMonitoring extends CustomerStep
         $targetId = $this->monitoring->registerTarget($instance->subdomain, $url);
 
         $this->recordResource($run, $instance->host, 'monitoring_target_id', $targetId);
-        $instance->monitoringTargets()->create([
-            'external_id' => $targetId,
-            'url' => $url,
-            'status' => 'up',
-        ]);
+        $instance->monitoringTargets()->firstOrCreate(
+            ['external_id' => $targetId],
+            ['url' => $url, 'status' => 'up'],
+        );
 
         return StepResult::advance();
     }

app/Services/Monitoring/FakeMonitoringClient.php

@@ -7,11 +7,15 @@ class FakeMonitoringClient implements MonitoringClient
     /** @var array<string, string> id => url */
     public array $targets = [];
 
-    private int $counter = 1;
-
     public function registerTarget(string $name, string $url): string
     {
-        $id = 'mon-'.$this->counter++;
+        // Idempotent by URL — a retry after a crash returns the same target id.
+        $existing = array_search($url, $this->targets, true);
+        if ($existing !== false) {
+            return $existing;
+        }
+
+        $id = 'mon-'.substr(sha1($url), 0, 12);
         $this->targets[$id] = $url;
 
         return $id;

app/Services/Proxmox/FakeProxmoxClient.php

@@ -59,6 +59,9 @@ class FakeProxmoxClient implements ProxmoxClient
     /** @var array<int, string> */
     public array $cloudInitCalls = [];
 
+    /** @var array<int, array<string, mixed>> vmid => params */
+    public array $cloudInitParams = [];
+
     /** @var array<int, string> */
     public array $resizeCalls = [];
 
@@ -96,6 +99,7 @@ class FakeProxmoxClient implements ProxmoxClient
     public function setCloudInit(string $node, int $vmid, array $params): void
     {
         $this->cloudInitCalls[] = $vmid;
+        $this->cloudInitParams[$vmid] = $params;
     }
 
     public function resizeDisk(string $node, int $vmid, string $disk, string $size): void

app/Services/Proxmox/HttpProxmoxClient.php

@@ -141,14 +141,22 @@ class HttpProxmoxClient implements ProxmoxClient
 
     public function createBackupJob(string $node, int $vmid, string $schedule): string
     {
-        $data = $this->http()->asForm()->post('/cluster/backup', [
+        // Deterministic job id → creating it twice (crash/retry) is idempotent.
+        $jobId = 'clupilot-'.$vmid;
+
+        $response = $this->http()->asForm()->post('/cluster/backup', [
+            'id' => $jobId,
             'vmid' => $vmid,
             'schedule' => $schedule,
             'storage' => 'local',
             'mode' => 'snapshot',
             'enabled' => 1,
-        ])->throw()->json('data');
+        ]);
 
-        return is_string($data) ? $data : (string) ($data['id'] ?? 'backup-'.$vmid);
+        if ($response->failed() && ! str_contains($response->body(), 'already')) {
+            $response->throw();
+        }
+
+        return $jobId;
     }
 }

tests/Feature/Provisioning/CustomerStepsTest.php

@@ -154,6 +154,8 @@ it('configures cloud-init and resizes the disk', function () {
     ['run' => $run] = reservedRun();
     expect(app(ConfigureCloudInit::class)->execute($run)->type)->toBe('advance')
         ->and($s['pve']->cloudInitCalls)->toContain(101)
+        ->and($s['pve']->cloudInitParams[101]['cores'])->toBe(2)      // start plan
+        ->and($s['pve']->cloudInitParams[101]['memory'])->toBe(4096)
         ->and($s['pve']->resizeCalls)->not->toBeEmpty();
 });