Support ultrawide layout with equal columns and taiji branding.

Use 50/50 mode workspace columns, widen content to 1920px on fish screens, replace header logo with taiji icon, and add full-page taiji backdrop.

Co-authored-by: Cursor <cursoragent@cursor.com>

components/footer.tsx

@@ -1,9 +1,12 @@
 import React from "react";
 import { VERSION } from "@/lib/constant";
+import { APP_CONTAINER } from "@/lib/layout";
 
 function Footer() {
   return (
-    <footer className="mx-auto flex items-center gap-1 text-xs text-muted-foreground/80">
+    <footer
+      className={`${APP_CONTAINER} relative z-10 flex items-center justify-center gap-1 py-4 text-xs text-muted-foreground/80`}
+    >
       <span className="italic">心诚则灵</span>
       <span className="text-muted-foreground/60">·</span>
       <span>知命阁 v{VERSION}</span>