fix(dialogs): Enter in Poll, Schedule, Report dialogs no longer discards input (#315)

Several dialogs are <Box as="form"> with the header ✕ (folds IconButton,
no type attribute, so a submit button) as the form's first button. On
implicit submission, Enter in a text field "clicked" ✕, closing the dialog
and throwing away what was typed (a poll's question and answers, a
schedule, a report reason).

The header close/cancel IconButtons now have type="button": Create Poll,
Schedule Message, Report User, Report Room, Account Data editor, State
Event editor, device verification setup, and the message delete/report
dialogs.

Verified headless: in Create Poll, typing a question and pressing Enter
used to close the dialog; now it stays open with the question kept.

Fixes #315

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017PCb59uY3UKqDqt7B6hzd5

src/app/features/room/message/Message.tsx

@@ -710,7 +710,13 @@ export const MessageDeleteItem = as<
                     Delete Message
                   </Text>
                 </Box>
-                <IconButton size="300" onClick={handleClose} radii="300" aria-label="Close">
+                <IconButton
+                  type="button"
+                  size="300"
+                  onClick={handleClose}
+                  radii="300"
+                  aria-label="Close"
+                >
                   <Icon src={Icons.Cross} />
                 </IconButton>
               </Header>
@@ -850,7 +856,13 @@ export const MessageReportItem = as<
                     Report Message
                   </Text>
                 </Box>
-                <IconButton size="300" onClick={handleClose} radii="300" aria-label="Close">
+                <IconButton
+                  type="button"
+                  size="300"
+                  onClick={handleClose}
+                  radii="300"
+                  aria-label="Close"
+                >
                   <Icon src={Icons.Cross} />
                 </IconButton>
               </Header>