[QA] ✅ VERIFIED - All acceptance criteria met. Dependencies install successfully (bcrypt 4.3.0, passlib 1.7.4, python-jose 3.5.0), all imports work correctly, no conflicts with existing packages, requirements.txt properly formatted with stable version pins. All 348 tests pass with no regressions. Ready for production. Full report: /tmp/qa-PPLX-46.md

## Changes Made Added the following dependencies to `backend/requirements.txt`: - `bcrypt>=4.0.0` - Already used by auth code (`backend/routers/auth.py:19`) but was not declared as a dependency - `passlib[bcrypt]>=1.7.4` - High-level password hashing library (FastAPI-recommended) - `python-jose[cryptography]>=3.5.0` - JWT token generation/validation library ## Verification 1. **Dependencies installed without conflicts**: `pip install -r requirements.txt` succeeded 2. **Imports verified**: - `from passlib.context import CryptContext` - SUCCESS - `from jose import jwt` - SUCCESS 3. **All 348 existing tests pass**: No regressions introduced ## Notes - The existing code uses `bcrypt` directly (imported at `backend/routers/auth.py:19`) and `PyJWT` (imported as `jwt`) - Added `bcrypt` to requirements.txt since it was being used but not declared - The new `passlib[bcrypt]` and `python-jose[cryptography]` packages can be used for future auth enhancements ## Files Modified - `backend/requirements.txt:14-16` - Added 3 new dependency lines