Fix liuyao UX: CSS coins, region auto-select, and clearer AI flow.

Replace missing coin images with CSS 3D coins, auto-select city on province change, expand Shandong cities, and improve AI interpretation prompts after six casts.

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

components/shared/hexagram-input.tsx

@@ -191,9 +191,14 @@ export default function HexagramInput({
         <div className="flex flex-col items-center gap-3 sm:flex-row">
           <Hexagram list={hexagramList} />
           {complete && (
-            <Button size="sm" variant="outline" onClick={handleReset}>
-              重新起卦
-            </Button>
+            <>
+              <p className="text-sm text-muted-foreground sm:max-w-[10rem]">
+                六爻已齐，请在下方点击「AI 解读」
+              </p>
+              <Button size="sm" variant="outline" onClick={handleReset}>
+                重新起卦
+              </Button>
+            </>
           )}
         </div>
       )}