Improve tweet read reliability and test coverage

src/lib/extract-tweet-id.ts

@@ -0,0 +1,12 @@
+/**
+ * Extract tweet ID from a Twitter/X URL or return the input unchanged if it's already an ID.
+ */
+export function extractTweetId(input: string): string {
+	// If it's a URL, extract the tweet ID
+	const urlMatch = input.match(/(?:twitter\.com|x\.com)\/\w+\/status\/(\d+)/);
+	if (urlMatch) {
+		return urlMatch[1];
+	}
+	// Assume it's already an ID
+	return input;
+}