[BUG] Claude GitHub App repo access not detected after fresh reinstall — repo picker still prompts to install

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

The Claude Code (web, claude.ai/code) repository picker still shows the "Install the Claude GitHub App" prompt / no repositories, even after fully uninstalling and reinstalling the GitHub App fresh with full repository access.

What Should Happen?

After confirming the Claude GitHub App is installed and configured with "All repositories" access on my GitHub account, the repository picker should recognize the installation and list my repositories.

Error Messages/Logs

No error message shown — the picker simply displays "No repositories available" and/or prompts to install the GitHub App again, even though it's already installed.

Steps to Reproduce

1. Go to claude.ai/code and click "+ Select repository..."
2. Picker shows "No repositories available" with a prompt to install the Claude GitHub App
3. Install the Claude GitHub App via github.com/apps/claude/installations/new on personal account (qsaraneth-cyber), granting "All repositories" access
4. Confirm in GitHub Settings → Applications that the app shows as installed and configured with "All repositories" access
5. Disconnect and reconnect the GitHub connector in Claude.ai → Settings → Connectors
6. Return to the repo picker in Claude Code — it still shows "No repositories available" / prompts to install the app again
7. As a further test: fully uninstalled the Claude GitHub App and reinstalled it fresh — same result

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

N/A — using claude.ai/code (web), not the CLI

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Other

Additional Information

GitHub username: qsaraneth-cyber
Account type: Personal
This appears to match the backend repo-indexing issue reported in #27155, #57161, and #65601. Could someone trigger a backend repository index reset for my account?