Replace dog branding with Daniel portrait

[tecxbro]

What changed

• Replaced the dog image used by the README and dashboard favicon with the supplied Daniel portrait.
• Rebuilt the 1280×640 social preview with the portrait while preserving the existing Daniel title, tagline, and neon layout.
• Removed the obsolete animated dog asset.

Why

Daniel’s public-facing visual identity should use the supplied portrait instead of the dog mascot.

Validation

• npm run validate
• Branding guard passed
• Typecheck passed
• 12 test files / 70 tests passed
• Production dashboard build passed
• Confirmed no remaining dog, puppy, mascot, or daniel.gif references in current product-facing assets and docs