fix(auth): truncate password to 72 chars to prevent bcrypt 500 error

backend/auth/dependencies.py

@@ -39,7 +39,8 @@ def hash_password(plain: str) -> str:
 
 
 def verify_password(plain: str, hashed: str) -> bool:
-    return pwd_context.verify(plain, hashed)
+    # Truncate to 72 bytes to prevent bcrypt 500 errors
+    return pwd_context.verify(plain[:72], hashed)
 
 
 # ── JWT helpers ───────────────────────────────────────────────────────────────