Detection Engineering Visuals Pack

Included visuals:
- detection-engineering-operating-model
- detection-content-lifecycle
- detection-engineering-value-flow
- detection-engineering-maturity-progression

Each visual is included as both PNG and SVG for report, slide, and document use.
Recommended repo placement:
- docs/03_visuals/

Suggested replacements for older visuals:
- Replace old maturity chart with detection-engineering-maturity-progression
- Replace old lifecycle diagram with detection-content-lifecycle
- Replace old SOC workflow diagram with detection-engineering-value-flow
- Use detection-engineering-operating-model as the main strategy/program visual