#88 Advanced: load custom user CSS

[Anonymous]

Originally created by: kristofferR

Summary

Add an opt-in advanced feature that loads a user-owned custom CSS file into the Messenger webview. Provide an easy way to open or reveal the file and apply changes on reload.

Custom CSS should be best-effort and clearly unsupported across Facebook DOM changes. A missing or invalid file must never prevent Carrier from starting.

Reference

• bankjaneo/caprine creates and opens custom.css from its menu: https://github.com/bankjaneo/caprine/blob/b9e97b3e512c474e70047656df9292eb07710415/source/menu.ts#L218-L239
• It injects the file when present: https://github.com/bankjaneo/caprine/blob/b9e97b3e512c474e70047656df9292eb07710415/source/index.ts#L613-L631

Decide file location, injection lifecycle, and Settings UX when this is picked up.

[Anonymous]

Ticket changed by: kristofferR

• status: open --> closed

[Anonymous]

Originally posted by: kristofferR

Fixed in [#140]. Added safe, reloadable Custom CSS support (Settings → Advanced) with origin/size/UTF-8 guards.