Lambda runtime: python3.10 → python3.14
Docker base image: public.ecr.aws/lambda/python:3.10 → python:3.14
Poetry: 1.2.2 → 1.8.4
pyproject.toml: python ^3.10 → ^3.14, ruff target py310 → py314
Removed obsolete backport dependencies (exceptiongroup, tomli, typing-extensions)