Dialogs close from a button and rise from the bottom on phones

DModal draws a close button (✕, named by CloseText) beside its heading, in a header that stays in view while the box
scrolls; a long list of who liked a post left only the thin margins around the box to tap out of it. A new
ResponsiveBottom placement makes the box a sheet from the bottom below md and keeps it in the middle from md; the
report, liked-by and boosted-by, edit history and public notice dialogs use it. Boxes are at most 100dvh tall, so a
phone's browser bars don't cut them, and a bottom sheet leaves 3rem above itself and clears the home indicator. The
report dialog gets a Cancel button.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LsXgEaXee4GCU1hwYgPJXw

Components/PublicNoticeHost.razor

@@ -3,7 +3,7 @@
 
 @* The one-time notice before a persona's first reaction or poll vote, and before it first joins an event
    (PublicNoticeService), in MainLayout. *@
-<DModal IsOpen="Notices.IsAsking" IsOpenChanged="Closed" CloseOnBackdrop="false" CloseText="@Localizer["Close"]">
+<DModal Placement="DModalPlacement.ResponsiveBottom" IsOpen="Notices.IsAsking" IsOpenChanged="Closed" CloseOnBackdrop="false" CloseText="@Localizer["Close"]">
 	<Heading>@(Notices.Act == PublicAct.Participation ? Localizer["Joining an event is public"] : Localizer["Reactions and votes are public"])</Heading>
 	<ChildContent>
 		<p class="text-sm">