perf: optimize rust acceleration paths

Rust vs Python benchmark results:

- RSS: Rust 0.299 ms/loop vs Python 7.913 ms/loop, 26.47x faster

- Filter: Rust 12.740 ms/loop vs Python 57.187 ms/loop, 4.49x faster

- MetaInfo: Rust 64.680 ms/loop vs Python 316.158 ms/loop, 4.89x faster

- Indexer agsvpt: Rust 145.76 ms vs Python 3686.50 ms, 25.29x faster

- Indexer pttime: Rust 166.51 ms vs Python 4019.87 ms, 24.14x faster

- Indexer chdbits: Rust 161.17 ms vs Python 3604.28 ms, 22.36x faster

- Indexer iptorrents: Rust 77.82 ms vs Python 17615.52 ms, 226.36x faster

Validation:

- cargo fmt/check/test for rust/moviepilot_rust

- pytest Rust-related coverage: tests/test_rust_accel.py tests/test_torrent_filter.py tests/test_metainfo.py tests/test_indexer_spider_search_url.py tests/test_workflow_fetch_rss.py

- tests/run.py legacy suite

- pylint app/ --errors-only

app/helper/rss.py

@@ -228,6 +228,37 @@ class RssHelper:
         },
     }
 
+    def __decode_fast_text(self, raw_data: bytes, ret) -> Optional[str]:
+        """
+        使用响应声明编码或 UTF-8 快速解码，优先服务 Rust 解析快路径。
+        """
+        seen_encodings = set()
+        for encoding in (getattr(ret, "encoding", None), "utf-8"):
+            if not encoding or encoding in seen_encodings:
+                continue
+            seen_encodings.add(encoding)
+            try:
+                return raw_data.decode(encoding)
+            except UnicodeDecodeError:
+                continue
+        return None
+
+    def __parse_with_rust(self, ret_xml: Optional[str]) -> Optional[list]:
+        """
+        调用 Rust RSS 解析器，并统一处理基础 XML 校验和最大条目限制。
+        """
+        if not ret_xml or not ret_xml.strip():
+            return None
+        ret_xml_stripped = ret_xml.strip()
+        if not ret_xml_stripped.startswith('<'):
+            return None
+        rust_items = rust_accel.parse_rss_items(ret_xml, self.MAX_RSS_ITEMS + 1)
+        if rust_items is None:
+            return None
+        if len(rust_items) > self.MAX_RSS_ITEMS:
+            logger.warning(f"RSS条目过多: 超过{self.MAX_RSS_ITEMS}，仅处理前{self.MAX_RSS_ITEMS}个")
+        return rust_items[:self.MAX_RSS_ITEMS]
+
     def parse(self, url, proxy: bool = False,
               timeout: Optional[int] = 15, headers: dict = None, ua: str = None) -> Union[List[dict], None, bool]:
         """
@@ -270,21 +301,26 @@ class RssHelper:
                     return False
 
                 if raw_data:
-                    try:
-                        result = chardet.detect(raw_data)
-                        encoding = result['encoding']
-                        # 解码为字符串
-                        ret_xml = raw_data.decode(encoding)
-                    except Exception as e:
-                        logger.debug(f"chardet解码失败：{str(e)}")
-                        # 探测utf-8解码
-                        match = re.search(r'encoding\s*=\s*["\']([^"\']+)["\']', ret.text)
-                        if match:
-                            encoding = match.group(1)
-                            if encoding:
-                                ret_xml = raw_data.decode(encoding)
-                        else:
-                            ret.encoding = ret.apparent_encoding
+                    ret_xml = self.__decode_fast_text(raw_data, ret)
+                    rust_items = self.__parse_with_rust(ret_xml)
+                    if rust_items is not None:
+                        return rust_items
+                    if not ret_xml:
+                        try:
+                            result = chardet.detect(raw_data)
+                            encoding = result['encoding']
+                            # 解码为字符串
+                            ret_xml = raw_data.decode(encoding)
+                        except Exception as e:
+                            logger.debug(f"chardet解码失败：{str(e)}")
+                            # 探测utf-8解码
+                            match = re.search(r'encoding\s*=\s*["\']([^"\']+)["\']', ret.text)
+                            if match:
+                                encoding = match.group(1)
+                                if encoding:
+                                    ret_xml = raw_data.decode(encoding)
+                            else:
+                                ret.encoding = ret.apparent_encoding
                 if not ret_xml:
                     ret_xml = ret.text
 
@@ -299,11 +335,9 @@ class RssHelper:
                     logger.error("RSS内容不是有效的XML格式")
                     return False
 
-                rust_items = rust_accel.parse_rss_items(ret_xml, self.MAX_RSS_ITEMS + 1)
+                rust_items = self.__parse_with_rust(ret_xml)
                 if rust_items is not None:
-                    if len(rust_items) > self.MAX_RSS_ITEMS:
-                        logger.warning(f"RSS条目过多: 超过{self.MAX_RSS_ITEMS}，仅处理前{self.MAX_RSS_ITEMS}个")
-                    return rust_items[:self.MAX_RSS_ITEMS]
+                    return rust_items
 
                 # 使用lxml.etree解析XML
                 parser = None