[cmccomb]

Summary

• Add the owner-supplied v17 primary and horizontal SVG logo files unchanged.
• Display the horizontal logo in the README with a white background so the navy wordmark is readable in GitHub light and dark themes.
• Document which variant to use for square and wide placements.

Verification

• Confirmed both source SVGs are byte-identical to the Desktop downloads.
• Parsed all three SVGs and checked for scripts and external references.
• Rendered and visually inspected the primary, horizontal, and README versions.
• Ran git diff --check.

Documentation and artwork only; no Python behavior changed.