feat: 작업 관리 시스템 및 TBM 공정/작업 통합

## Backend Changes
- Create tasks table with work_type_id FK to work_types
- Add taskModel, taskController, taskRoutes for task CRUD
- Update tbmModel to support work_type_id and task_id
- Add migrations for tasks table and TBM integration

## Frontend Changes
- Create task management admin page (tasks.html, task-management.js)
- Update TBM modal to include work type (공정) and task (작업) selection
- Add cascading dropdown: work type → task selection
- Display work type and task info in TBM session cards
- Update sidebar navigation in all admin pages

## Database Schema
- tasks: task_id, work_type_id, task_name, description, is_active
- tbm_sessions: add work_type_id, task_id columns with FKs
- Foreign keys maintain referential integrity with work_types and tasks

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

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

web-ui/pages/admin/codes.html

@@ -41,6 +41,12 @@
               <span class="menu-text">작업장 관리</span>
             </a>
           </li>
+          <li class="menu-item">
+            <a href="/pages/admin/tasks.html">
+              <span class="menu-icon">📋</span>
+              <span class="menu-text">작업 관리</span>
+            </a>
+          </li>
           <li class="menu-item active">
             <a href="/pages/admin/codes.html">
               <span class="menu-icon">🏷️</span>