v1.3.0

Remove qwen-code dependency and fix critical bugs

The plugin never needed qwen-code installed — it already has its own OAuth Device Flow (RFC 8628). This release removes the unnecessary fallback to qwen-code credentials, fixes critical bugs, and cleans up dead code.

Bugs fixed

• Silent slow_down handling: pollDeviceToken() returned null when the server requested slow_down, preventing the polling interval from increasing. Now correctly throws SlowDownError
• Non-portable Bun.sleep: Doesn't work on Node.js. Replaced with standard setTimeout
• refreshToken || '': Treated empty string as falsy. Fixed to use ??
• Incorrect REAUTH_HINT: Referenced non-existent qwen-code auth login

Dead code removed

• Fallback to ~/.qwen/oauth_creds.json from qwen-code
• Functions: loadCredentials, getValidCredentials, getOpenCodeAuthPath, generateState, checkExistingCredentials
• Unused types: QwenOAuthState, QwenModelId, ChatMessage, ChatCompletionRequest, ChatCompletionResponse, StreamChunk
• Files: src/plugin/utils.ts, src/plugin/client.ts
• Dependency: open (not imported by any active code)

Result

• -492 lines, +33 lines
• Zero runtime dependencies
• Compatible with Node.js >=20 and Bun

Closes #5