Strip template artifacts and fix lint errors

Remove npm lockfile, unused create-next-app SVGs, project-specific
next.config workarounds, and the unused @remixicon/react and date-fns deps.

Replace three set-state-in-effect patterns with useSyncExternalStore in
use-mobile, DialogPortal, and Carousel; the carousel change also fixes a
leaked reInit listener. yarn lint and yarn build are clean.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01K8PmydbW6A1S2Tw3SFc3Cg

hooks/use-mobile.ts

@@ -1,19 +1,18 @@
 import * as React from "react"
 
 const MOBILE_BREAKPOINT = 768
+const MOBILE_QUERY = `(max-width: ${MOBILE_BREAKPOINT - 1}px)`
+
+function subscribe(onStoreChange: () => void) {
+  const mql = window.matchMedia(MOBILE_QUERY)
+  mql.addEventListener("change", onStoreChange)
+  return () => mql.removeEventListener("change", onStoreChange)
+}
 
 export function useIsMobile() {
-  const [isMobile, setIsMobile] = React.useState<boolean | undefined>(undefined)
-
-  React.useEffect(() => {
-    const mql = window.matchMedia(`(max-width: ${MOBILE_BREAKPOINT - 1}px)`)
-    const onChange = () => {
-      setIsMobile(window.innerWidth < MOBILE_BREAKPOINT)
-    }
-    mql.addEventListener("change", onChange)
-    setIsMobile(window.innerWidth < MOBILE_BREAKPOINT)
-    return () => mql.removeEventListener("change", onChange)
-  }, [])
-
-  return !!isMobile
+  return React.useSyncExternalStore(
+    subscribe,
+    () => window.matchMedia(MOBILE_QUERY).matches,
+    () => false
+  )
 }