system-locked violation types (alpha & terlambat) + proporsional poin alpha per jam

- Migration: add is_system column to violation_types, mark alpha & terlambat
- DestroyType guard: system types cannot be deleted
- UpdateType guard: slug tetap walau nama diubah untuk system types
- UI: delete button hidden, badge lock untuk system types
- Seeder: ViolationTypeDefaultsSeeder untuk fresh deploy
- AttendanceController: lookup by slug (alpha/terlambat) instead of fuzzy match
- Alpha auto-violation: poin proporsional per jam (round((points/10)*count), min 1)
- Terlambat auto-violation: poin fix sesuai jenis (2 poin)
- Also handles both A (alpha) and T (terlambat) statuses for auto-violations

database/seeders/ViolationTypeDefaultsSeeder.php

@@ -0,0 +1,53 @@
+<?php
+
+namespace Database\Seeders;
+
+use App\Models\ViolationCategory;
+use App\Models\ViolationType;
+use Illuminate\Database\Seeder;
+
+class ViolationTypeDefaultsSeeder extends Seeder
+{
+    public function run(): void
+    {
+        // Cari kategori ringan (ID 1 biasanya)
+        $ringan = ViolationCategory::where('slug', 'ringan')
+            ->orWhere('name', 'like', '%ringan%')
+            ->first();
+
+        if (!$ringan) {
+            $this->command->warn('Kategori "Ringan" tidak ditemukan. Buat kategori Ringan dulu.');
+            return;
+        }
+
+        // Alpha
+        ViolationType::updateOrCreate(
+            ['slug' => 'alpha'],
+            [
+                'name' => 'Alpha - Tidak hadir tanpa keterangan',
+                'category_id' => $ringan->id,
+                'points' => 15,
+                'default_sanction' => 'Peringatan lisan / teguran BK',
+                'description' => 'Pelanggaran otomatis dari sistem presensi ketika siswa tidak hadir tanpa keterangan.',
+                'is_active' => true,
+                'is_system' => true,
+            ]
+        );
+
+        // Terlambat
+        ViolationType::updateOrCreate(
+            ['slug' => 'terlambat'],
+            [
+                'name' => 'Terlambat',
+                'category_id' => $ringan->id,
+                'points' => 2,
+                'default_sanction' => 'Peringatan lisan',
+                'description' => 'Pelanggaran otomatis dari sistem presensi ketika siswa terlambat.',
+                'is_active' => true,
+                'is_system' => true,
+            ]
+        );
+
+        $this->command->info('System violation types (alpha & terlambat) seeded/updated.');
+    }
+}