Add swift-bird runner

[ryan-token]

Pull Request

Type of Change

• Add a new runner
• Fix or improve an existing runner
• Other (site, docs, tooling)

Summary

Adds swift-bird, a common swift (Apus apus) in a shallow dive.

Eight frames at 48x36 make one full wingbeat: wings extended on the downstroke, folded on the recovery, forked tail fanning, body bobbing. Since the cycle is one beat, the flapping speeds up with CPU load.

It is monochrome, so it takes the menu bar's tint color in light and dark.

The artwork is original vector geometry, not traced. It is a drawing of the bird and inspired by Apple's Swift logo, but it is not Apple's Swift logo nor does it use any of its artwork.

Checklist for Adding a Runner

• I have read CONTRIBUTING.md and followed the steps described there.
• The runner is my original work, or I hold the rights to it, and I consent to its distribution under this repository's license (Apache-2.0).
• The runner does NOT contain third-party intellectual property (e.g., Pokémon, Mario, or other copyrighted/trademarked characters).
• Files are placed at runners/<runner-name>/ as <runner-name>-frames.zip, metadata.json, and preview.png.
• All frames are PNG files named <runner-name>-frame-<N>.png (numbered from 0), with a height of exactly 36px, a width between 10px and 100px, and all frames share the same size.
• The zip contains only the frames — no .DS_Store, __MACOSX/, or ._* entries.
• metadata.json contains the correct author, displayName, type (monochrome or color), and tags.
• preview.png is an animated PNG (APNG), 36px tall, at most 100px wide, and animates correctly.
• runners/manifest.json includes the new runner name and stays sorted alphabetically.