[MartinRain]

Summary

Fix report-specific PDF branding presets being ignored by the BEC (full and summary), Sharing, Permissions, Mail Flow, and Shadow AI PDF reports.

• Forward the configured brandingPresetId from the UI through the backend to tenant naming and PDF rendering.
• Apply distinct full and summary branding presets to the BEC evidence ZIP PDFs.
• Preserve fallback to global branding when no report-specific preset is configured.
• Keep changes scoped to affected report components and endpoints, without modifying the shared PDF renderer or adding Graph requests.

Validation

• Pester: 18/18 targeted tests passed.
• Vitest: 10/10 targeted tests passed.
• Functional: All affected reports successfully tested in a running CIPP instance.

Fixes #967