Final grep: 0 send_result in active code. 3 historical refs in
error_handling.md (intentional, in the 'Historical deprecation' note).
Test verification: 100/101 tests pass in the 26 files renamed by this
track. 1 pre-existing failure in test_headless_service.py due to
missing credentials.toml (verified against origin/master baseline
where it also fails - unrelated to the rename).
7 broader suite failures all pre-existing (all FileNotFoundError on
credentials.toml, confirmed against origin/master baseline).
Track verification:
- git grep send_result: 0 in active code (3 historical intentional)
- Full test suite: matches pre-rename baseline (7 pre-existing failures
unrelated to the rename, 0 new regressions)
