fix(ui): align chat send button and widen team members table

- Chat: change send/stop buttons from size-icon (36px) to size-icon-lg
  (40px) to match textarea height with py-3 padding
- Teams: remove max-w-2xl on members tab to fill parent width

ui/web/src/components/chat/chat-input.tsx

@@ -57,7 +57,7 @@ export function ChatInput({ onSend, onAbort, isRunning, disabled }: ChatInputPro
       {isRunning ? (
         <Button
           variant="destructive"
-          size="icon"
+          size="icon-lg"
           onClick={onAbort}
           title="Stop generation"
         >
@@ -65,7 +65,7 @@ export function ChatInput({ onSend, onAbort, isRunning, disabled }: ChatInputPro
         </Button>
       ) : (
         <Button
-          size="icon"
+          size="icon-lg"
           onClick={handleSend}
           disabled={!value.trim() || disabled}
           title="Send message"

ui/web/src/pages/teams/team-members-tab.tsx

@@ -53,7 +53,7 @@ export function TeamMembersTab({ members, onAddMember, onRemoveMember }: TeamMem
   };
 
   return (
-    <div className="max-w-2xl space-y-6">
+    <div className="space-y-6">
       {onAddMember && (
         <div className="space-y-2">
           <Label className="inline-flex items-center gap-1">