Context

Sub-task of #402 (Wave 2: expose remaining nested *FieldNames request parameters as CLI options).

The strategies.get request type declares 16 nested *FieldNames parameters that have no dedicated kebab-case CLI option. They are currently registered in NESTED_FIELDNAMES_EXCLUSIONS (tests/test_api_coverage.py) with the #402 marker so test_every_nested_fieldnames_param_has_cli_option passes.

This is one of the two largest groups in Wave 2 (along with ads get) — splitting into smaller PRs (e.g. by Cpa / Cpc / PayForConversion families) is acceptable as long as each PR removes the corresponding NESTED_FIELDNAMES_EXCLUSIONS rows.

Scope — WSDL parameters to expose

Reference implementation

• direct_cli/commands/adextensions.py — original --callout-field-names pattern (PR [codex] Add adextensions CalloutFieldNames flag #359).
• direct_cli/commands/sitelinks.py:114 and direct_cli/commands/keywordbids.py — Wave 1 examples (PR feat(api): expose separate *FieldNames params for sitelinks and keywordbids #403): each option parses CSV via parse_csv_strings, rejects empty input with click.UsageError, sets the WSDL key only when non-empty, and (for multi-FieldNames resources) falls back to the matching COMMON_FIELDS[<service>]["<XxxFieldNames>"] default.
• direct_cli/utils.py — COMMON_FIELDS dict: extend with a dict[str, list[str]] entry keyed by the WSDL request param.

Acceptance

• Each WSDL parameter above has a kebab-case --<name>-field-names flag on direct strategies get.
• Empty CSV (--<name>-field-names "") raises click.UsageError.
• Corresponding rows in NESTED_FIELDNAMES_EXCLUSIONS removed.
• New dry-run tests in tests/test_dry_run.py mirroring the sitelinks_get / keywordbids_get shape.
• pytest tests/test_api_coverage.py::test_every_nested_fieldnames_param_has_cli_option passes without those exclusions.
• CHANGELOG.md entry under Unreleased.