refactor: migrate to monorepo structure with Docker, PocketBase, and e2e tests

- Reorganize into apps/, packages/, docs/, e2e/, pocketbase/ directories
- Add Dockerfiles for web, worker, and PocketBase services
- Add docker-compose.yml for local orchestration
- Add turbo.json for monorepo task management
- Add Playwright e2e test infrastructure
- Add PocketBase backend with migrations
- Remove Vite/Next.js/ESLint/PostCSS config files
- Update package.json with workspace dependencies
- Add .env.example and .dockerignore

apps/web/app/api/attachments/upload/route.ts

@@ -0,0 +1,40 @@
+import { NextRequest, NextResponse } from 'next/server';
+import { withAuth, createErrorResponse } from '@/lib/auth';
+import { createPocketBaseClient } from '@/lib/pocketbase';
+
+// POST /api/attachments/upload — Upload file attachment
+export const POST = withAuth(async (request: NextRequest, _user) => {
+  try {
+    const formData = await request.formData();
+    const file = formData.get('file') as File | null;
+    const taskId = formData.get('task_id') as string | null;
+
+    if (!file) {
+      return createErrorResponse('VALIDATION_ERROR', 'File is required', 400);
+    }
+
+    if (!taskId) {
+      return createErrorResponse('VALIDATION_ERROR', 'task_id is required', 400);
+    }
+
+    // Check file size (5MB limit)
+    if (file.size > 5 * 1024 * 1024) {
+      return createErrorResponse('FILE_TOO_LARGE', 'File size must be less than 5MB', 400);
+    }
+
+    const pb = createPocketBaseClient();
+
+    // Upload to PocketBase
+    const attachment = await pb.collection('task_attachments').create({
+      task_id: taskId,
+      file,
+      filename: file.name,
+      mime_type: file.type,
+      size: file.size,
+    });
+
+    return NextResponse.json(attachment, { status: 201 });
+  } catch {
+    return createErrorResponse('UPLOAD_FAILED', 'Failed to upload file', 500);
+  }
+});