docs: complete brownfield reference documentation #217

Job	Run time
Gitleaks (secret scan)	14s
OSV-Scanner (SCA)	7s
jscpd (duplication < 3% on touched code)	17s
SBOM (SPDX + CycloneDX)	21s
Semgrep (SAST)	20s
Trivy (filesystem + container scan)	14s
	1m 33s

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