feat(API): Position API 추가 (직급/직책 통합)

- Position 모델 생성 (type: rank | title)
- PositionService: CRUD + reorder 구현
- PositionController: REST API 엔드포인트
- Swagger 문서 작성 (PositionApi.php)
- 마이그레이션: positions 테이블 + common_codes 등록
- routes/api.php에 라우트 등록

Phase L-3 (직급관리), L-4 (직책관리) 백엔드 완료

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

database/migrations/2025_12_30_091821_create_positions_table.php

@@ -0,0 +1,30 @@
+<?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::create('positions', function (Blueprint $table) {
+            $table->id();
+            $table->foreignId('tenant_id')->comment('테넌트 ID');
+            $table->string('type', 20)->comment('유형: rank(직급), title(직책)');
+            $table->string('name', 50)->comment('명칭');
+            $table->integer('sort_order')->default(0)->comment('정렬 순서');
+            $table->boolean('is_active')->default(true)->comment('활성화 여부');
+            $table->timestamps();
+            $table->softDeletes();
+
+            $table->index(['tenant_id', 'type', 'sort_order']);
+            $table->unique(['tenant_id', 'type', 'name', 'deleted_at'], 'positions_tenant_type_name_unique');
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::dropIfExists('positions');
+    }
+};

database/migrations/2025_12_30_091822_add_position_type_to_common_codes.php

@@ -0,0 +1,38 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Support\Facades\DB;
+
+return new class extends Migration
+{
+    public function up(): void
+    {
+        $now = now();
+
+        // position_type 코드 그룹 (직급/직책 구분)
+        $positionTypes = [
+            ['code' => 'rank', 'name' => '직급', 'sort_order' => 1],
+            ['code' => 'title', 'name' => '직책', 'sort_order' => 2],
+        ];
+
+        foreach ($positionTypes as $item) {
+            DB::table('common_codes')->updateOrInsert(
+                ['code_group' => 'position_type', 'code' => $item['code']],
+                [
+                    'code_group' => 'position_type',
+                    'code' => $item['code'],
+                    'name' => $item['name'],
+                    'sort_order' => $item['sort_order'],
+                    'is_active' => true,
+                    'created_at' => $now,
+                    'updated_at' => $now,
+                ]
+            );
+        }
+    }
+
+    public function down(): void
+    {
+        DB::table('common_codes')->where('code_group', 'position_type')->delete();
+    }
+};