docs: enrich OOM-fix streaming-refactor plan + gitignore fix #163

Job	Run time
Semgrep (SAST)	21s
Gitleaks (secret scan)	14s
OSV-Scanner (SCA)	6s
SBOM (SPDX + CycloneDX)	16s
jscpd (duplication < 3% on touched code)	17s
Trivy (filesystem + container scan)	9s
	1m 23s

Provide feedback