feat(port): add nova port

[nexiumbiz-debug]

Resolves #143

What changed

• Added a Nova port that builds an Aura.novaextension bundle.
• Generates four Nova CSS theme variants under Themes/:
  • Aura Dark
  • Aura Dark (Soft Text)
  • Aura Soft Dark
  • Aura Soft Dark (Soft Text)
• Added the generated packages/nova output and a README with installation steps.

Notes

• The Nova theme structure follows Panic's theme docs: themes live in a Themes folder and use .css files.
• This is an AI-assisted contribution prepared with Codex for Chris / nexiumbiz-debug.
• I could not capture an in-app Nova screenshot from this Windows environment, so validation here is limited to generated output and repo tests.

Verification

• NODE_OPTIONS=--use-system-ca corepack yarn install --frozen-lockfile
• NODE_OPTIONS=--use-system-ca DEBUG=aura* NODE_ENV=production corepack yarn aura build only nova
• NODE_OPTIONS=--use-system-ca corepack yarn test
• git diff --check

[nexiumbiz-debug]

Quick follow-up on this Nova port. The generated extension and repo tests were passing when I opened it, and the PR is still mergeable with no review blockers showing from my side. Happy to adjust the bundle shape, theme naming, or generated output if you want it organized differently.