Port to Safari

[Sri-Ln]

The outlier, and realistically its own mini-project rather than a port.

Prerequisites, to confirm before starting

• Access to a macOS machine with Xcode
• An Apple Developer Program membership, currently 99 USD per year

Acceptance criteria

• Converted via safari-web-extension-converter
• Audit which extension APIs Safari actually supports. Its implementation lags Chrome and Firefox, and something in the current design may need a fallback.
• Submitted to the App Store

Worth deciding deliberately whether Safari's user share justifies the cost, rather than porting because the list said three browsers.