feat: [roadmap] 중장기 계획 메뉴 및 전용 페이지 개발

- 모델: AdminRoadmapPlan, AdminRoadmapMilestone
- 서비스: RoadmapPlanService, RoadmapMilestoneService
- FormRequest: Store/Update Plan/Milestone 4개
- 컨트롤러: Blade(RoadmapController), API(Plan/Milestone) 3개
- 라우트: web.php, api.php에 roadmap 라우트 추가
- Blade 뷰: 대시보드, 목록, 생성, 수정, 상세, 파셜 테이블 6개
- HTMX 기반 필터링/페이지네이션, 마일스톤 인라인 추가/토글

routes/web.php

@@ -48,6 +48,7 @@
 use App\Http\Controllers\PostController;
 use App\Http\Controllers\ProfileController;
 use App\Http\Controllers\ProjectManagementController;
+use App\Http\Controllers\RoadmapController;
 use App\Http\Controllers\QuoteFormulaController;
 use App\Http\Controllers\RoleController;
 use App\Http\Controllers\RolePermissionController;
@@ -357,6 +358,15 @@
         Route::get('/import', [ProjectManagementController::class, 'import'])->name('import');
     });
 
+    // 중장기 계획 (Blade 화면만)
+    Route::prefix('roadmap')->name('roadmap.')->group(function () {
+        Route::get('/', [RoadmapController::class, 'index'])->name('index');
+        Route::get('/plans', [RoadmapController::class, 'plans'])->name('plans.index');
+        Route::get('/plans/create', [RoadmapController::class, 'createPlan'])->name('plans.create');
+        Route::get('/plans/{id}', [RoadmapController::class, 'showPlan'])->name('plans.show');
+        Route::get('/plans/{id}/edit', [RoadmapController::class, 'editPlan'])->name('plans.edit');
+    });
+
     // 일일 스크럼 (Blade 화면만)
     Route::prefix('daily-logs')->name('daily-logs.')->group(function () {
         Route::get('/', [DailyLogController::class, 'index'])->name('index');