Add versioned Audita config support

docs/roadmap.md

@@ -205,6 +205,25 @@ Update architecture documentation to explain:
 
 Introduce a versioned configuration file and clarify which settings are stable CLI flags, which settings belong in config, and which settings should remain environment-only.
 
+## Implementation status (2026-05-13)
+
+This workstream is now implemented for runtime loading and basic command surface:
+- versioned YAML file config with strict unknown-field rejection and `version: 1` validation;
+- runtime config-source behavior for `audita process`:
+  - defaults;
+  - config file (`--config`, then `AUDITA_CONFIG`, then `/etc/audita/config.yml` if present);
+  - environment overrides;
+  - CLI overrides;
+- explicit missing-file errors for `--config` and `AUDITA_CONFIG`, with non-fatal missing default-path behavior;
+- `api_key_env` support in file config for proposal and validation LLM credentials;
+- config command surface:
+  - `audita config validate --config <path>`
+  - `audita config print-effective [--config <path>]`
+- redacted effective-config behavior preserved across diagnostics and config printing;
+- compatibility environment variables and lower-level process flags remain available.
+
+This status update applies only to versioned config support and config commands. Output schema registries, broader public-contract work, validator refactors, prompt-asset registries, utilization diagnostics, and correction ledgers remain planned.
+
 This phase should happen early because later workstreams need clean config locations for prompt registry settings, output schema selection, validator settings, diagnostics settings, and concurrency tuning.
 
 ## Configuration precedence