scope web-only dialog width caps to web

now that android tablet sheets lay content out at the real 640dp canvas,
unscoped maxWidth caps on dialog content (previously inert on phones)
became visible as narrow left-aligned content. wrap them in web() to
match the established pattern (BlockDialog, ModerationDetailsDialog).
also covers gtMobile-gated caps, which were live on android tablets
because useBreakpoints has no native split.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/components/dialogs/Embed.tsx

@@ -8,7 +8,7 @@ import {Trans} from '@lingui/react/macro'
 import {EMBED_SCRIPT} from '#/lib/constants'
 import {niceDate} from '#/lib/strings/time'
 import {toShareUrl} from '#/lib/strings/url-helpers'
-import {atoms as a, useTheme} from '#/alf'
+import {atoms as a, useTheme, web} from '#/alf'
 import {Button, ButtonIcon, ButtonText} from '#/components/Button'
 import * as Dialog from '#/components/Dialog'
 import * as SegmentedControl from '#/components/forms/SegmentedControl'
@@ -103,7 +103,7 @@ function EmbedDialogInner({
   }, [i18n, postUri, postCid, record, timestamp, postAuthor, colorMode])
 
   return (
-    <Dialog.Inner label={_(msg`Embed post`)} style={[{maxWidth: 500}]}>
+    <Dialog.Inner label={_(msg`Embed post`)} style={[web({maxWidth: 500})]}>
       <View style={[a.gap_lg]}>
         <View style={[a.gap_sm]}>
           <Text style={[a.text_2xl, a.font_bold]}>