refactor: ignore trailing separator for permalink router (#2632)

#### What type of PR is this?
/kind improvement
/area core
/milestone 2.0
#### What this PR does / why we need it:
permalink 路由匹配时自动忽略末尾分隔符
例如
/archives  匹配到 /archives
/archives/ 匹配到 /archives

#### Special notes for your reviewer:
/cc @halo-dev/sig-halo 
#### Does this PR introduce a user-facing change?

```release-note
None
```

src/main/java/run/halo/app/theme/router/RadixRouterTree.java

@@ -125,7 +125,7 @@ public HandlerFunction<ServerResponse> match(ServerRequest request) {
      * TODO Optimize parameter route matching query.
      * Router 仅匹配请求方法和请求的 URL 路径, 形如 /?p=post-name 是 URL query，而不是 URL 路径的一部分。
      */
-    private String pathToFind(ServerRequest request) {
+    static String pathToFind(ServerRequest request) {
         String requestPath = processRequestPath(request.path());
         MultiValueMap<String, String> queryParams = request.queryParams();
         // 文章的 permalink 规则需要对 p 参数规则特殊处理
@@ -141,6 +141,7 @@ private String pathToFind(ServerRequest request) {
                 requestPath = requestPath.substring(0, i);
             }
         }
+        requestPath = StringUtils.removeEnd(requestPath, "/");
         return StringUtils.prependIfMissing(requestPath, "/");
     }
 
@@ -177,7 +178,7 @@ private static Map<String, String> mergePathVariables(Map<String, String> oldVar
         }
     }
 
-    private String processRequestPath(String requestPath) {
+    private static String processRequestPath(String requestPath) {
         String path = StringUtils.prependIfMissing(requestPath, "/");
         return UriUtils.decode(path, StandardCharsets.UTF_8);
     }

src/main/java/run/halo/app/theme/router/strategy/ArchivesRouteStrategy.java

@@ -5,6 +5,7 @@
 
 import java.util.List;
 import java.util.Map;
+import org.apache.commons.lang3.StringUtils;
 import org.springframework.stereotype.Component;
 import org.springframework.web.reactive.function.server.HandlerFunction;
 import org.springframework.web.reactive.function.server.ServerRequest;
@@ -64,7 +65,7 @@ public HandlerFunction<ServerResponse> getHandler() {
     @Override
     public List<String> getRouterPaths(String prefix) {
         return List.of(
-            prefix,
+            StringUtils.prependIfMissing(prefix, "/"),
             PathUtils.combinePath(prefix, "/page/{page:\\d+}"),
             PathUtils.combinePath(prefix, "/{year:\\d{4}}"),
             PathUtils.combinePath(prefix, "/{year:\\d{4}}/page/{page:\\d+}"),

src/test/java/run/halo/app/theme/router/RadixRouterTreeTest.java

@@ -0,0 +1,44 @@
+package run.halo.app.theme.router;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.net.URI;
+import java.net.URISyntaxException;
+import org.junit.jupiter.api.Test;
+import org.springframework.http.HttpMethod;
+import org.springframework.mock.web.reactive.function.server.MockServerRequest;
+
+/**
+ * Tests for {@link RadixRouterTree}.
+ *
+ * @author guqing
+ * @since 2.0.0
+ */
+class RadixRouterTreeTest {
+
+    @Test
+    void pathToFind() throws URISyntaxException {
+        MockServerRequest request =
+            MockServerRequest.builder().uri(new URI("/archives"))
+                .method(HttpMethod.GET).build();
+        String path = RadixRouterTree.pathToFind(request);
+        assertThat(path).isEqualTo("/archives");
+
+        request = MockServerRequest.builder().uri(new URI("/archives/"))
+            .method(HttpMethod.GET).build();
+        assertThat(RadixRouterTree.pathToFind(request)).isEqualTo("/archives");
+
+        request = MockServerRequest.builder().uri(new URI("/archives/page/1"))
+            .method(HttpMethod.GET).build();
+        assertThat(RadixRouterTree.pathToFind(request)).isEqualTo("/archives");
+
+        request = MockServerRequest.builder().uri(new URI("/"))
+            .method(HttpMethod.GET).build();
+        assertThat(RadixRouterTree.pathToFind(request)).isEqualTo("/");
+
+        request = MockServerRequest.builder().uri(new URI("/"))
+            .queryParam("p", "fake-post")
+            .method(HttpMethod.GET).build();
+        assertThat(RadixRouterTree.pathToFind(request)).isEqualTo("/?p=fake-post");
+    }
+}