Retire Chronicle target profiles

[juaristi22]

Summary

• remove Chronicle-owned target profiles and target-resolution APIs now that Microcosm owns selection contracts
• limit consumer artifacts to fact rows and manifest hashes
• retire the target-profile agent lane and update the surrounding documentation and tests

Testing

• uv run --locked --extra dev ruff check .
• uv run --locked pytest -q --ignore=tests/test_chronicle_bundle.py --ignore=tests/test_chronicle_source_package.py (548 passed, 1 skipped)
• uv run --locked pytest -q tests/test_chronicle_source_package.py plus the focused consumer, contract, governance, and import tests (167 passed)
• uv run --locked pytest -q tests/test_chronicle_bundle.py -k 'not test_build_bundle_writes_merged_consumer_contract' (8 passed, 1 deselected)
• wheel build and import smoke test
• end-to-end build-consumer-artifact CLI smoke test

The 171,855-row full-bundle golden test was started locally but interrupted after eight minutes while computing the build ID. CI runs the complete test suite.

Fixes #172