spa config: apply catalog settings to splunk_config.yml

Summary

Apply feature-catalog snippets into an env splunk_config.yml from the CLI, without a skill.

#53 ships lookup only: spa features list / show / search / keys. Records include keys, a YAML snippet, and merge (deep vs replace) so an apply command can write the env config the same way spa-create-config does by hand today.

Ship

• Operator command (tentative spa config set ID, stem at pickup) that merges the catalog snippet into $SPA_ENV_DIR/config/splunk_config.yml.
• Flag/placeholder values for snippets; never print secrets; Splunkbase stays lookup('env', ...).
• Then spa validate (or call it).
• Skills may call this instead of patching YAML themselves.
• Tests: apply setting.os onto a topology+provider skeleton; refuse unknown ids; no credential echo.

Related

• Blocked by #53
• Apps install/search remains #59 / #68

Notes

Pickup-ready after #53. Never print secrets. Skills and agents call spa only.

Start by reviewing the feature-catalog work in #53 and the existing CLI path for configuration commands. Implement the catalog apply flow for $SPA_ENV_DIR/config/splunk_config.yml, including merge behavior, placeholders, validation, and secret-safe errors. Add tests for applying setting.os to a topology and provider skeleton, rejecting unknown IDs, and avoiding credential output.