Refactor WEBMENTION_TOKEN handling: read from file and remove environment configuration

src/components/Webmentions.astro

@@ -1,8 +1,24 @@
 ---
-import { WEBMENTION_TOKEN } from 'astro:env/server';
+import { readFileSync } from 'node:fs';
 import { DEFAULT_LOCALE, type Locale } from '~/consts';
 import { getLocaleFromUrl, t } from '~/i18n/ui';
 
+function readTokenFromFile(): string | undefined {
+	const paths = ['/app/.webmention-token', '.webmention-token'];
+	for (const p of paths) {
+		try {
+			const raw = readFileSync(p, 'utf-8').trim();
+			if (raw) return raw;
+		} catch {
+			// file not present, try next
+		}
+	}
+	return undefined;
+}
+
+const FILE_TOKEN = readTokenFromFile();
+const WEBMENTION_TOKEN = FILE_TOKEN ?? (import.meta.env as Record<string, string | undefined>).WEBMENTION_TOKEN;
+
 interface WMAuthor {
 	name?: string;
 	url?: string;