Add the files that were referenced in the previous commit but not
yet staged:

- src/alberta_framework/core/sarsa.py: SARSAAgent, SARSAConfig,
  SARSAState, learning loops (episode, continuing, scan)
- tests/test_sarsa.py: 30 tests covering init, action selection,
  update logic, epsilon decay, bounding, serialization, scan
- examples/The Alberta Plan/Step4/sarsa_cartpole.py: SARSA on
  CartPole-v1 comparing Autostep vs LMS
- examples/The Alberta Plan/Step4/sarsa_trading.py: SARSA on
  gym-anytrading FOREX/STOCKS with README-style position plots,
  SARSA vs Random comparison, and continuing-mode Autostep vs LMS
- docs/guide/sarsa-control.md: architecture, usage, daemon integration