feat: certificate template management and generation (Fasa 7)

- CertificateService: Intervention Image v3 text overlay on template
- GenerateCertificateJob: queued generation with retry logic
- SendCertificateEmailJob: stub (implemented in Fasa 8)
- CertificateTemplateController: upload, config editor, preview, test generate
- Admin/CertificateController: list, generate-all, email-all
- Public/CertificateController: show with questionnaire gate, download
- DejaVuSans fonts bundled under resources/fonts
- Views: admin template/certificate management, public certificate download

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

app/Http/Controllers/Public/CertificateController.php

@@ -3,9 +3,86 @@
 namespace App\Http\Controllers\Public;
 
 use App\Http\Controllers\Controller;
+use App\Models\Certificate;
+use App\Models\QuestionnaireResponse;
+use Illuminate\Http\RedirectResponse;
 use Illuminate\Http\Request;
+use Illuminate\Http\Response;
+use Illuminate\Support\Facades\Storage;
+use Illuminate\View\View;
 
 class CertificateController extends Controller
 {
-    //
+    public function show(string $cert_token): View|RedirectResponse
+    {
+        $certificate = Certificate::where('token', $cert_token)
+            ->with(['participant', 'program', 'template'])
+            ->firstOrFail();
+
+        $program     = $certificate->program;
+        $participant = $certificate->participant;
+
+        // Check questionnaire gate
+        $pq = $program->questionnaire()->first();
+        $needsQuestionnaire = $pq && $pq->is_confirmed;
+        $hasAnswered = false;
+
+        if ($needsQuestionnaire) {
+            $hasAnswered = QuestionnaireResponse::where('program_id', $program->id)
+                ->where('participant_id', $participant->id)
+                ->exists();
+        }
+
+        // Find active QR code for questionnaire redirect
+        $qrCode = $program->qrCode;
+
+        return view('public.certificate.show', compact(
+            'certificate', 'program', 'participant', 'pq',
+            'needsQuestionnaire', 'hasAnswered', 'qrCode'
+        ));
+    }
+
+    public function download(string $cert_token): Response|RedirectResponse
+    {
+        $certificate = Certificate::where('token', $cert_token)
+            ->with(['participant', 'program'])
+            ->firstOrFail();
+
+        if (! $certificate->isGenerated()) {
+            return back()->with('error', 'Sijil belum sedia untuk dimuat turun.');
+        }
+
+        if (! $certificate->file_path || ! Storage::disk('local')->exists($certificate->file_path)) {
+            return back()->with('error', 'Fail sijil tidak dijumpai. Sila hubungi penganjur.');
+        }
+
+        // Check questionnaire gate
+        $program = $certificate->program;
+        $pq = $program->questionnaire()->first();
+
+        if ($pq && $pq->is_confirmed) {
+            $hasAnswered = QuestionnaireResponse::where('program_id', $program->id)
+                ->where('participant_id', $certificate->participant_id)
+                ->exists();
+
+            if (! $hasAnswered) {
+                $qrCode = $program->qrCode;
+                $redirectTo = $qrCode
+                    ? route('public.questionnaire.show', [$qrCode->token, $certificate->participant->uuid])
+                    : back();
+                return redirect($redirectTo)->with('info', 'Sila jawab borang penilaian terlebih dahulu.');
+            }
+        }
+
+        $certificate->recordDownload();
+
+        $content  = Storage::disk('local')->get($certificate->file_path);
+        $filename = 'Sijil-' . str($certificate->participant->name)->slug() . '.jpg';
+
+        return response($content, 200, [
+            'Content-Type'        => 'image/jpeg',
+            'Content-Disposition' => 'attachment; filename="' . $filename . '"',
+            'Content-Length'      => strlen($content),
+        ]);
+    }
 }