docs: add argus.yml configuration reference

Add comprehensive config-reference.md documenting all argus.yml
top-level keys, scanner properties, reporting, execution, containers,
and DAST sections. Link from CLAUDE.md, README.md, and architecture.yaml.

Author: eFAILution

.ai/architecture.yaml

@@ -384,6 +384,8 @@ directory_structure:
   "tests/": "Test infrastructure"
   "tests/fixtures/": "Shared test data"
   "docs/": "Detailed documentation"
+  "docs/config-reference.md": "Full argus.yml configuration specification"
+  "argus-config.schema.json": "JSON Schema for argus.yml validation and IDE support"
   "hardening-dagger/": "Python reporting utility (separate module)"
 
 constraints:

CLAUDE.md

@@ -440,7 +440,7 @@ reporters:
   - sarif
 ```
 
-See `argus.example.yml` for a complete configuration reference.
+See `argus.example.yml` for a quick-start template, or [Configuration Reference](docs/config-reference.md) for the full specification.
 
 ### Composite Action Usage (GitHub Actions)
 
@@ -552,7 +552,8 @@ Examples are automatically validated by `.github/workflows/test-examples-functio
 - `argus/scanners/__init__.py` - Scanner registry
 - `argus/reporters/__init__.py` - Reporter registry
 - `argus.yml` - Project scan configuration
-- `argus.example.yml` - Configuration reference with all options
+- `argus.example.yml` - Quick-start configuration template
+- `docs/config-reference.md` - Full `argus.yml` specification
 - `version.yaml` - Single version source for releases
 - `renovate.yaml` - Dependency update configuration
 - `CONTRIBUTING.md` - Composite actions contributor guide

README.md

@@ -175,6 +175,7 @@ See [examples/github-enterprise/](examples/github-enterprise/) for complete GHES
 
 ### User Guides
 
+- [Configuration Reference](docs/config-reference.md) - Full `argus.yml` specification
 - [Scanner Reference](docs/scanners.md) - Complete configuration for all scanners
 - [Container Scanning](docs/container-scanning.md) - Config-driven matrix container scanning
 - [Failure Control](docs/failure-control.md) - Severity-based workflow failure configuration