feat: [approval] 결재관리 Phase 1 MVP 구현

- 모델 4개: Approval, ApprovalStep, ApprovalForm, ApprovalLine
- ApprovalService: 목록/CRUD/워크플로우(상신/승인/반려/회수) 비즈니스 로직
- ApprovalApiController: JSON API 엔드포인트 (기안함/결재함/완료함/참조함)
- ApprovalController: Blade 뷰 컨트롤러 (HX-Redirect 처리)
- 뷰 8개: drafts, pending, completed, references, create, edit, show
- partials: _status-badge, _step-progress, _approval-line-editor
- api.php/web.php 라우트 등록

app/Http/Controllers/ApprovalController.php

@@ -0,0 +1,113 @@
+<?php
+
+namespace App\Http\Controllers;
+
+use App\Services\ApprovalService;
+use Illuminate\Http\Request;
+use Illuminate\Http\Response;
+use Illuminate\View\View;
+
+class ApprovalController extends Controller
+{
+    public function __construct(
+        private readonly ApprovalService $service
+    ) {}
+
+    /**
+     * 기안함
+     */
+    public function drafts(Request $request): View|Response
+    {
+        if ($request->header('HX-Request')) {
+            return response('', 200)->header('HX-Redirect', route('approvals.drafts'));
+        }
+
+        return view('approvals.drafts');
+    }
+
+    /**
+     * 기안 작성
+     */
+    public function create(Request $request): View|Response
+    {
+        if ($request->header('HX-Request')) {
+            return response('', 200)->header('HX-Redirect', route('approvals.create'));
+        }
+
+        $forms = $this->service->getApprovalForms();
+        $lines = $this->service->getApprovalLines();
+
+        return view('approvals.create', compact('forms', 'lines'));
+    }
+
+    /**
+     * 기안 수정
+     */
+    public function edit(Request $request, int $id): View|Response
+    {
+        if ($request->header('HX-Request')) {
+            return response('', 200)->header('HX-Redirect', route('approvals.edit', $id));
+        }
+
+        $approval = $this->service->getApproval($id);
+
+        if (! $approval->isEditable() || $approval->drafter_id !== auth()->id()) {
+            abort(403, '수정할 수 없습니다.');
+        }
+
+        $forms = $this->service->getApprovalForms();
+        $lines = $this->service->getApprovalLines();
+
+        return view('approvals.edit', compact('approval', 'forms', 'lines'));
+    }
+
+    /**
+     * 결재 상세
+     */
+    public function show(Request $request, int $id): View|Response
+    {
+        if ($request->header('HX-Request')) {
+            return response('', 200)->header('HX-Redirect', route('approvals.show', $id));
+        }
+
+        $approval = $this->service->getApproval($id);
+
+        return view('approvals.show', compact('approval'));
+    }
+
+    /**
+     * 결재 대기함
+     */
+    public function pending(Request $request): View|Response
+    {
+        if ($request->header('HX-Request')) {
+            return response('', 200)->header('HX-Redirect', route('approvals.pending'));
+        }
+
+        return view('approvals.pending');
+    }
+
+    /**
+     * 참조함
+     */
+    public function references(Request $request): View|Response
+    {
+        if ($request->header('HX-Request')) {
+            return response('', 200)->header('HX-Redirect', route('approvals.references'));
+        }
+
+        return view('approvals.references');
+    }
+
+    /**
+     * 완료함
+     */
+    public function completed(Request $request): View|Response
+    {
+        if ($request->header('HX-Request')) {
+            return response('', 200)->header('HX-Redirect', route('approvals.completed'));
+        }
+
+        return view('approvals.completed');
+    }
+}