fix(feedback): Stop long error messages from resizing the feedback dialog - #23376

…alog

The error message container could both overflow the dialog and, above the
600px breakpoint, widen it past the viewport.

Two things caused it. `.form__right` is a `<fieldset>`, and the UA stylesheet
gives fieldsets `min-inline-size: min-content`, which stretches them to the
longest unbreakable word they contain. Separately, `.dialog__position` is
fixed with `inset: auto 0 0 auto`, so only its bottom and right edges are
anchored and its width is shrink-to-fit — meaning any descendant's intrinsic
width propagates up into the dialog's own width.

`min-width: 0` on the fieldset removes the UA floor. On the error container,
`width: 0` combined with `min-width: 100%` removes it from intrinsic sizing
altogether: percentages are ignored while intrinsic sizes are computed, so it
contributes 0 to that pass, then fills its container once the container's
width is known. `overflow-wrap: break-word` then breaks words too long for
the resulting box.

`overflow-wrap: anywhere` would replace both declarations on the error
container, but it needs Safari 15.4 and the SDK supports 15.0.

Verified in Chromium, WebKit and Firefox at 320/420/768/1024/1440px against
the default message, a long URL and a 200-character unbreakable token: the
dialog now matches its no-error width in every combination. Previously the
default `errorGenericText` alone widened it by ~135px at 768px and above.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>