by codex: feat. General Improvements

lib/claudeCredentials.ts

@@ -0,0 +1,19 @@
+const CLAUDE_SESSION_KEY_PATTERN = /^sk-ant-[A-Za-z0-9_-]+$/;
+
+export function validateClaudeSessionKey(value: string): string | null {
+  const key = value.trim();
+  if (!key.startsWith("sk-ant-")) {
+    return "Session key must start with sk-ant-";
+  }
+  if (key.length <= 40) {
+    return "Session key looks too short. Paste the complete cookie value.";
+  }
+  if (!CLAUDE_SESSION_KEY_PATTERN.test(key)) {
+    return "Session key contains unexpected characters. Check the pasted value.";
+  }
+  return null;
+}
+
+export function isClaudeSessionKeyValid(value: string): boolean {
+  return validateClaudeSessionKey(value) === null;
+}