feat(a11y): comprehensive icon button label sweep — 60+ remaining buttons labeled

C-1 complete sweep across all components and features:
- Call controls: mic mute/unmute, deafen/undeafen, video, screenshare, chat
- RoomInput: dismiss reply, attach file, sticker, emoji, GIF, location, toolbar
- Media viewers: close in image/pdf/text viewers and editors
- Settings dialogs: close buttons in all room/space/common settings panels
- Lobby: back, toggle member list, scroll to top, pack add/remove
- Auth: server picker, UIA flow cancel
- Upload cards: cancel uploads
- URL preview: prev/next buttons
- Members drawer: close + scroll to top
- RoomViewHeader: back, start call, toggle member list

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/app/features/common-settings/developer-tools/DevelopTools.tsx

@@ -92,7 +92,7 @@ export function DeveloperTools({ requestClose }: DeveloperToolsProps) {
             </Text>
           </Box>
           <Box shrink="No">
-            <IconButton onClick={requestClose} variant="Surface">
+            <IconButton onClick={requestClose} variant="Surface" aria-label="Close">
               <Icon src={Icons.Cross} />
             </IconButton>
           </Box>

src/app/features/common-settings/developer-tools/SendRoomEvent.tsx

@@ -118,7 +118,7 @@ export function SendRoomEvent({ type, stateKey, requestClose }: SendRoomEventPro
             </Chip>
           </Box>
           <Box shrink="No">
-            <IconButton onClick={requestClose} variant="Surface">
+            <IconButton onClick={requestClose} variant="Surface" aria-label="Close">
               <Icon src={Icons.Cross} />
             </IconButton>
           </Box>

src/app/features/common-settings/developer-tools/StateEventEditor.tsx

@@ -275,7 +275,7 @@ export function StateEventEditor({ type, stateKey, requestClose }: StateEventEdi
             </Chip>
           </Box>
           <Box shrink="No">
-            <IconButton onClick={requestClose} variant="Surface">
+            <IconButton onClick={requestClose} variant="Surface" aria-label="Close">
               <Icon src={Icons.Cross} />
             </IconButton>
           </Box>

src/app/features/common-settings/emojis-stickers/EmojisStickers.tsx

@@ -29,7 +29,7 @@ export function EmojisStickers({ requestClose }: EmojisStickersProps) {
             </Text>
           </Box>
           <Box shrink="No">
-            <IconButton onClick={requestClose} variant="Surface">
+            <IconButton onClick={requestClose} variant="Surface" aria-label="Close">
               <Icon src={Icons.Cross} />
             </IconButton>
           </Box>

src/app/features/common-settings/emojis-stickers/RoomPacks.tsx

@@ -218,6 +218,7 @@ export function RoomPacks({ onViewPack }: RoomPacksProps) {
                     size="300"
                     radii="Pill"
                     variant="Critical"
+                    aria-label="Undo remove pack"
                     onClick={() => handleUndoRemove(address)}
                     disabled={applyingChanges}
                   >
@@ -228,6 +229,7 @@ export function RoomPacks({ onViewPack }: RoomPacksProps) {
                     size="300"
                     radii="Pill"
                     variant="Secondary"
+                    aria-label="Remove pack"
                     onClick={() => handleRemove(address)}
                     disabled={applyingChanges}
                   >

src/app/features/common-settings/members/Members.tsx

@@ -161,7 +161,7 @@ export function Members({ requestClose }: MembersProps) {
             </Text>
           </Box>
           <Box shrink="No">
-            <IconButton onClick={requestClose} variant="Surface">
+            <IconButton onClick={requestClose} variant="Surface" aria-label="Close">
               <Icon src={Icons.Cross} />
             </IconButton>
           </Box>
@@ -278,6 +278,7 @@ export function Members({ requestClose }: MembersProps) {
               >
                 <IconButton
                   onClick={() => virtualizer.scrollToOffset(0)}
+                  aria-label="Scroll to top"
                   variant="Surface"
                   radii="Pill"
                   outlined

src/app/features/common-settings/permissions/PowersEditor.tsx

@@ -369,7 +369,7 @@ export function PowersEditor({ powerLevels, requestClose }: PowersEditorProps) {
             </Chip>
           </Box>
           <Box shrink="No">
-            <IconButton onClick={requestClose} variant="Surface">
+            <IconButton onClick={requestClose} variant="Surface" aria-label="Close">
               <Icon src={Icons.Cross} />
             </IconButton>
           </Box>