feat: add common utilities and feedback handling scripts

- Introduced common.js for shared functions including API calls, error reporting, and UI helpers.
- Implemented feedback.js for the feedback reporting page, including form handling and displaying feedback status.
- Added layout.js for managing galaxy and section layouts in the visualization.
- Created login.js for user authentication with session management.
- Developed search.js for term searching based on user input and synonyms.
- Implemented signup.js for user registration with validation and immediate login.

requirements.txt

@@ -0,0 +1,6 @@
+fastapi>=0.110
+uvicorn[standard]>=0.29
+pymupdf>=1.24
+# 테스트
+httpx
+pytest