Implements the autoresearch entry point requested in #907:
- `SystemExperiment` class in autoresearch.py encapsulates the
hypothesis → edit → tox → evaluate → commit/revert loop with
configurable target, metric, and budget
- `timmy learn` CLI command with --target, --metric, --budget,
--max-experiments, --dry-run, --tox-env, and --model flags
- Helper functions _extract_pass_rate() and _extract_coverage()
for built-in metric extraction from tox/pytest output
- program.md template in repo root for research direction
- Unit tests for SystemExperiment and the learn CLI command
Fixes#907
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
