[Bugs] **Short (in-app "Report a problem"):**

**Mood:** 😊
**Category:** Bugs

**Short (in-app "Report a problem"):**

**OAuth MCP servers broke after a recent app update.** All MCP servers configured with OAuth stopped authenticating — the "Sign in" button no longer appears in MCP settings, so the OAuth flow never starts. Bearer-token MCP servers still work fine.

This is a regression: it worked a few days ago (sign-in buttons were visible, OAuth servers authenticated fine), it broke right after an update, and my entire team is affected identically — so it's not a local cache/credential issue. The same OAuth servers still work via CLI (e.g. Claude CLI), confirming the servers are healthy and the bug is in the desktop app's OAuth flow specifically.

Expected: sign-in button appears → browser OAuth flow → server authenticates.

Actual: no button, no prompt, servers unusable.

**App version:** 1.0.69-0

OS: Windows. Impact: all OAuth MCP integrations unusable app-wide for the whole team.

---
| Field | Value |
| --- | --- |
| App version | 1.0.15 |
| OS | Windows 10.0.26200 |
| Theme | GitHub |
| Path | /chat |
| Tenure | Week 2 |

No source files or tests are mentioned. Reproduce the regression in MCP settings on Windows using app version 1.0.69-0, comparing an OAuth server with a bearer-token server and checking the browser flow. Done means OAuth MCP servers show a Sign in button, launch authentication, and authenticate successfully.

Do mô hình lập chỉ mục viết ra từ nội dung của issue.