feat(adapter): detect claude-login-required errors and expose errorCode/errorMeta

Add detectClaudeLoginRequired and extractClaudeLoginUrl to parse module.
Extract buildClaudeRuntimeConfig for reuse by both execute and the new
runClaudeLogin helper. Include errorCode: "claude_auth_required" and
errorMeta: { loginUrl } in execution results when login is needed.
Export runClaudeLogin from the package index.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/adapters/claude-local/src/server/index.ts

@@ -1,4 +1,4 @@
-export { execute } from "./execute.js";
+export { execute, runClaudeLogin } from "./execute.js";
 export { testEnvironment } from "./test.js";
 export { parseClaudeStreamJson, describeClaudeFailure, isClaudeUnknownSessionError } from "./parse.js";
 import type { AdapterSessionCodec } from "@paperclip/adapter-utils";