Issue #17 approved an Air Korea two-API flow with a region fallback, so this change adds a new fine-dust skill, wires it into the repo docs/setup surfaces, and includes a runnable helper plus fixtures/tests for repeatable verification.
Constraint: Must use the approved official Air Korea APIs and secure secret registration flow
Rejected: Use an unofficial air-quality API | issue follow-up explicitly approved the Air Korea two-API flow
Rejected: Require coordinates only | issue discussion required a practical fallback when precise location is unavailable
Confidence: high
Scope-risk: moderate
Directive: Keep the helper and docs aligned with Air Korea endpoint names and fallback order if the official API contract changes
Tested: npm run ci; python3 scripts/fine_dust.py report --station-file scripts/fixtures/fine-dust-stations.json --measurement-file scripts/fixtures/fine-dust-measurements.json --lat 37.5665 --lon 126.9780; python3 scripts/fine_dust.py report --station-file scripts/fixtures/fine-dust-stations.json --measurement-file scripts/fixtures/fine-dust-measurements.json --region-hint '서울 강남구'; python3 scripts/fine_dust.py --help; missing-secret error path without AIR_KOREA_OPEN_API_KEY
Not-tested: Live Air Korea API calls with a real AIR_KOREA_OPEN_API_KEY
Credential-bearing skills now point to a shared cross-platform setup based on sops plus age instead of a hosted password manager. The repo also gains a default setup skill and a small verification script so users can bring one encrypted secrets file to every relevant skill.
Constraint: The secret workflow must work on macOS, Linux, and Windows without mandatory vendor signup
Rejected: Keep 1Password CLI as the default | it requires account creation and sign-in
Rejected: Plaintext .env as the default | too easy to leak in a repo and too easy for tools to read at rest
Confidence: high
Scope-risk: moderate
Reversibility: clean
Directive: If a future skill needs stronger isolation than exec-env provides, expose a capability wrapper instead of injecting the raw secret
Tested: bash scripts/validate-skills.sh
Tested: npx --yes skills add . --list
Tested: bash scripts/check-setup.sh (expected failure without sops/age installed)
Not-tested: End-to-end sops encryption and exec-env flow on a machine with sops and age installed
Jeffrey (Dongkyu) Kim