fix: replace missing Vite favicon reference

[ubugeeei]

Finding

index.html still references /vite.svg, but the repo does not include that asset. This produces a broken favicon request in dev/prod.

Evidence

• index.html references /vite.svg.
• No vite.svg file exists in the repository.

Acceptance criteria

• Replace the favicon with an existing FrameScript asset or remove the broken reference.
• Verify app build still passes.

[ubugeeei]

対応済みです。修正は PR #1 / commit 9cf4498 に反映済みです。