Polish settings UI, add tooltips, replace timeAgo with date-fns

Clean up settings section design: consolidate backup cards, add
hover-reveal actions with tooltips, improve icon sizing across
components, and replace custom timeAgo helper with date-fns
formatDistanceToNow in webhook card.

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

app/(pages)/setup/page.tsx

@@ -24,7 +24,7 @@ const steps = [
           className="inline-flex items-center gap-1 font-medium text-primary underline decoration-primary/30 underline-offset-2 transition-colors hover:decoration-primary"
         >
           themoviedb.org
-          <IconExternalLink size={14} />
+          <IconExternalLink className="size-3.5" />
         </a>{" "}
         and sign up for a free account.
       </>
@@ -43,7 +43,7 @@ const steps = [
           className="inline-flex items-center gap-1 font-medium text-primary underline decoration-primary/30 underline-offset-2 transition-colors hover:decoration-primary"
         >
           Settings &rarr; API
-          <IconExternalLink size={14} />
+          <IconExternalLink className="size-3.5" />
         </a>{" "}
         and request an API key. Choose &ldquo;Developer&rdquo; when asked. You
         need the{" "}
@@ -133,7 +133,7 @@ export default function SetupPage() {
       {/* Header */}
       <motion.div variants={sectionVariants} className="space-y-3">
         <div className="inline-flex items-center gap-2 rounded-full border border-primary/20 bg-primary/5 px-3 py-1 text-xs font-medium text-primary">
-          <IconKey size={14} />
+          <IconKey className="size-3.5" />
           Setup required
         </div>
         <h1 className="font-display text-3xl tracking-tight sm:text-4xl">
@@ -188,12 +188,12 @@ export default function SetupPage() {
                         >
                           {copiedIdx === idx ? (
                             <>
-                              <IconCheck size={12} className="text-green-400" />
+                              <IconCheck className="size-3 text-green-400" />
                               Copied
                             </>
                           ) : (
                             <>
-                              <IconCopy size={12} />
+                              <IconCopy className="size-3" />
                               Copy
                             </>
                           )}
@@ -217,7 +217,7 @@ export default function SetupPage() {
           {configured === true ? (
             <div className="flex items-center gap-3">
               <div className="flex h-10 w-10 items-center justify-center rounded-full bg-green-500/10">
-                <IconCheck size={20} className="text-green-400" />
+                <IconCheck className="size-5 text-green-400" />
               </div>
               <div>
                 <p className="font-medium text-green-400">