GeezerVison

Problem

The 2FA/SMS code entry uses six independently focused text fields. Pasting a code only kept one digit (#587) and macOS one-time code autofill from Messages/Mail broke after the first digit because the system inserts the whole code into the focused field and the focus jumping between fields aborts the insertion (#788).

Fix

Rewrote PinCodeTextView around the standard one-time code pattern: a single invisible NSTextField with contentType = .oneTimeCode overlays the row and owns all input, while the digit boxes are display-only. Pasting now works from any state, the system autofill suggestion appears (field auto-focuses when the sheet opens) and inserts the full code, and pasting a full code over partially entered digits replaces them. The public PinCodeTextField SwiftUI API is unchanged.

Note: the SMS being deleted after autofill is the system "Clean Up Automatically" feature and not controllable by the app.

Testing

Verified with a headless harness driving the real field editor: paste into empty field, paste over partial input, paste with separators, digit by digit typing, backspace, overflow capping, autofill-style bulk insertText and external reset via the binding. App builds and runs.

Fixes #587
Fixes #788