feat(epub): align wxread css and overlay pagination behavior

Sources/RDReaderView/EPUBCore/RDEPUBWebView+FixedLayout.swift

@@ -61,7 +61,17 @@ extension RDEPUBWebView {
 
     /// 生成固定版式加载签名（用于去重相同请求）
     func fixedLayoutLoadSignature(publicationKey: String, request: RDEPUBFixedRenderRequest) -> String {
-        [
+        let searchSignature = [
+            request.searchPresentation?.keyword ?? "",
+            request.searchPresentation?.resources.map {
+                [
+                    $0.href,
+                    String($0.matchCount),
+                    String($0.activeLocalMatchIndex ?? -1)
+                ].joined(separator: "|")
+            }.joined(separator: ",") ?? ""
+        ].joined(separator: "#")
+        return [
             publicationKey,
             "fixed",
             request.spread.resources.map(\.href).joined(separator: "|"),
@@ -72,7 +82,8 @@ extension RDEPUBWebView {
             String(format: "%.2f", request.contentInset.bottom),
             String(format: "%.2f", request.contentInset.right),
             request.backgroundColorCSS ?? "",
-            request.fit.rawValue
+            request.fit.rawValue,
+            searchSignature
         ].joined(separator: "#")
     }