[mark-caii]

Motivation

Server SDKs send a flag selection on the agentless configuration request. System-tests needs its mock configuration endpoint to apply that selection to the shared ufc-config.json. UFC responses carry no tags, though, so the mock has nothing to filter by.

Jira: FFL-3567

Changes

• flag-selection/ufc-config-tags.json gives tags to three ufc-config.json flags (basic-flag, numeric_flag, experiment-flag), in the same {key, tags} shape as the flags in the vectors.
• ci/validate-flag-selection.py checks the file's shape and rejects any key that is missing from ufc-config.json.
• validate-flag-selection.yml also runs when ufc-config.json changes.
• Both READMEs document the file.

Decisions

• The tags live in their own file rather than in ufc-config.json, so the UFC fixture keeps matching what the server returns.
• The selection vectors keep their own six flags and do not run against this flag set. The file exists only so a mock can filter the shared configuration.

Checklist

• JSON files are valid (no syntax errors)
• New test cases reference existing flags in ufc-config.json
• New flags have corresponding test cases in evaluation-cases/ (no new flags)
• Expected results match the flag configuration logic

python3 ci/validate-flag-selection.py passes, and it fails when the tags file names an unknown key.