feat(toolrate): rebrand to toolr + logo links home

- visible brand text changed to toolr (sidebar, mobile header, topbar
  fallback, login, 404, home heading, index.html title/og/twitter meta)
- brand logo now links to / in sidebar, mobile header, login, 404
- internal identifiers unchanged: package name, localStorage key

artifacts/toolrate/src/pages/home.tsx

@@ -21,7 +21,7 @@ export default function Home() {
     <Layout>
       <div className="space-y-8 pb-8">
         <div>
-          <h1 className="text-3xl font-bold tracking-tight mb-2">Welcome to ToolRate</h1>
+          <h1 className="text-3xl font-bold tracking-tight mb-2">Welcome to toolr</h1>
           <p className="text-muted-foreground">The community hub where engineers honestly rate the tools they use daily.</p>
         </div>
 

artifacts/toolrate/src/pages/login.tsx

@@ -46,10 +46,10 @@ export default function Login() {
       </div>
       <div className="w-full max-w-sm space-y-6">
         <div className="flex flex-col items-center gap-2 text-center">
-          <div className="flex items-center gap-2 text-primary font-bold text-2xl">
+          <Link href="/" className="flex items-center gap-2 text-primary font-bold text-2xl">
             <Wrench className="w-7 h-7" />
-            <span>ToolRate</span>
-          </div>
+            <span>toolr</span>
+          </Link>
           <p className="text-muted-foreground text-sm">Sign in to your account</p>
         </div>
 

artifacts/toolrate/src/pages/not-found.tsx

@@ -8,10 +8,10 @@ export default function NotFound() {
     <div className="min-h-screen w-full flex items-center justify-center bg-background">
       <Card className="w-full max-w-md mx-4">
         <CardContent className="pt-6 pb-6 text-center">
-          <div className="flex items-center justify-center gap-2 text-primary font-bold text-xl mb-6">
+          <Link href="/" className="flex items-center justify-center gap-2 text-primary font-bold text-xl mb-6">
             <Wrench className="w-6 h-6" />
-            <span>ToolRate</span>
-          </div>
+            <span>toolr</span>
+          </Link>
           <h1 className="text-6xl font-bold text-muted-foreground/30 mb-2">404</h1>
           <p className="text-muted-foreground mb-6">This page doesn't exist.</p>
           <Link href="/">