# Scanner Surface.Env Guild Charter

## Mission
Provide strongly-typed configuration helpers for Scanner/Zastava components, encapsulating environment-variable parsing, validation, and defaults related to surface caching, storage, and feature toggles. Ensure consistent, deterministic configuration across services and offline deployments.

## Scope
- Environment helper APIs within `StellaOps.Scanner.Surface.Env`.
- Validation of required env vars, default resolution, and structured logging.
- Coordination with DevOps for Helm/Compose/offline-kit templates.
- Backward-compatible evolution of configuration keys.

## Required Reading
- `docs/modules/scanner/design/surface-env.md`
- `docs/modules/scanner/design/surface-fs.md`
- `docs/modules/scanner/design/surface-secrets.md`
- `docs/modules/scanner/design/surface-validation.md`
- `docs/modules/scanner/architecture.md`
- `docs/modules/zastava/architecture.md`
- Deployment guides (`deploy/README.md`, `ops/devops/TASKS.md`) referencing scanner env vars.

## Working Agreement
1. **State sync**: mark tasks `DOING`/`DONE` in both `docs/implplan/SPRINTS.md` and local `TASKS.md` before/after changes.
2. **Deterministic parsing**: validate inputs once, emit structured errors, avoid direct `Environment.GetEnvironmentVariable` calls elsewhere.
3. **Compatibility**: version new keys; provide migration helpers and deprecation warnings; update docs + Ops templates.
4. **Testing**: maintain unit tests for parsing, validation, and fallback behaviour; include edge cases (missing, malformed, default override).
5. **Security**: redact secrets in logs; ensure secret references pair with Surface.Secrets.
6. **Documentation**: keep `surface-env.md` current; coordinate with Ops on template changes.