fix(settings): add spacing to Sim Keys toggle and replace Sim Mailer icon with Send

Add 24px top margin to the "Allow personal Sim keys" toggle so it doesn't
sit right below the empty state. Replace the Mail envelope icon for Sim
Mailer with a new Send (paper plane) icon matching the emcn icon style.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/sim/app/workspace/[workspaceId]/settings/components/api-keys/api-keys.tsx

@@ -321,7 +321,7 @@ export function ApiKeys() {
       {/* Allow Personal API Keys Toggle - Fixed at bottom */}
       {!isLoading && canManageWorkspaceKeys && (
         <Tooltip.Provider delayDuration={150}>
-          <div className='mt-auto flex items-center justify-between'>
+          <div className='mt-[24px] flex items-center justify-between'>
             <div className='flex items-center gap-[8px]'>
               <span className='font-medium text-[14px] text-[var(--text-secondary)]'>
                 Allow personal Sim keys

apps/sim/app/workspace/[workspaceId]/settings/navigation.ts

@@ -8,6 +8,7 @@ import {
   KeySquare,
   LogIn,
   Mail,
+  Send,
   Server,
   Settings,
   ShieldCheck,
@@ -130,7 +131,7 @@ export const allNavigationItems: NavigationItem[] = [
   {
     id: 'inbox',
     label: 'Sim Mailer',
-    icon: Mail,
+    icon: Send,
     section: 'system',
     requiresHosted: true,
     selfHostedOverride: isInboxEnabled,

apps/sim/components/emcn/icons/index.ts

@@ -60,6 +60,7 @@ export { Redo } from './redo'
 export { Rocket } from './rocket'
 export { Rows3 } from './rows3'
 export { Search } from './search'
+export { Send } from './send'
 export { Server } from './server'
 export { Settings } from './settings'
 export { ShieldCheck } from './shield-check'

apps/sim/components/emcn/icons/send.tsx

@@ -0,0 +1,25 @@
+import type { SVGProps } from 'react'
+
+/**
+ * Send icon component - paper plane / arrow
+ * @param props - SVG properties including className, fill, etc.
+ */
+export function Send(props: SVGProps<SVGSVGElement>) {
+  return (
+    <svg
+      width='24'
+      height='24'
+      viewBox='-1 -2 24 24'
+      fill='none'
+      stroke='currentColor'
+      strokeWidth='1.75'
+      strokeLinecap='round'
+      strokeLinejoin='round'
+      xmlns='http://www.w3.org/2000/svg'
+      {...props}
+    >
+      <path d='M19.5 1.5L9 12' />
+      <path d='M19.5 1.5L13.5 19.5L9 12L1.5 8.5L19.5 1.5Z' />
+    </svg>
+  )
+}