feat: upgrade to astro v3

Upgrade to astro v3. Update dependencies. Fix codes and features due to migration.

BREAKING CHANGE: Astro v3

resolve #111

src/components/Header.astro

@@ -3,9 +3,6 @@ import { LOGO_IMAGE, SITE } from "@config";
 import Hr from "./Hr.astro";
 import LinkButton from "./LinkButton.astro";
 
-import logoPNG from "/assets/logo.png";
-import logoSVG from "/assets/logo.svg";
-
 export interface Props {
   activeNav?: "posts" | "tags" | "about" | "search";
 }
@@ -21,8 +18,8 @@ const { activeNav } = Astro.props;
         {
           LOGO_IMAGE.enable ? (
             <img
-              src={LOGO_IMAGE.svg ? logoSVG : logoPNG}
-              alt="AstroPaper Logo"
+              src={`/assets/${LOGO_IMAGE.svg ? "logo.svg" : "logo.png"}`}
+              alt={SITE.title}
               width={LOGO_IMAGE.width}
               height={LOGO_IMAGE.height}
             />
@@ -78,7 +75,7 @@ const { activeNav } = Astro.props;
               href="/search"
               className={`focus-outline p-3 sm:p-1 ${
                 activeNav === "search" ? "active" : ""
-              }`}
+              } flex`}
               ariaLabel="search"
               title="Search"
             >