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

Dockerfile.pocketbase

@@ -0,0 +1,20 @@
+FROM alpine:latest
+
+ARG POCKETBASE_VERSION=0.25.5
+
+RUN apk add --no-cache unzip wget ca-certificates
+
+RUN wget -O /tmp/pocketbase.zip https://github.com/pocketbase/pocketbase/releases/download/v${POCKETBASE_VERSION}/pocketbase_${POCKETBASE_VERSION}_linux_amd64.zip \
+    && unzip /tmp/pocketbase.zip -d /usr/local/bin/ \
+    && rm /tmp/pocketbase.zip \
+    && chmod +x /usr/local/bin/pocketbase
+
+# Copy migrations
+COPY pocketbase/pb_migrations/ /pb_migrations/
+
+EXPOSE 8090
+
+HEALTHCHECK --interval=30s --timeout=10s --retries=3 --start-period=10s \
+  CMD wget --no-verbose --tries=1 --spider http://localhost:8090/api/health || exit 1
+
+ENTRYPOINT ["/usr/local/bin/pocketbase", "serve", "--http=0.0.0.0:8090", "--dir=/pb_data", "--publicDir=/pb_public", "--migrationDir=/pb_migrations"]