🐞 Bug Summary

When an OAuth authorization_code gateway transitions from offline → online, set_gateway_state re-initializes the MCP connection without a valid OAuth token, receives an empty tool list, and deletes all existing tools, resources, prompts, and their virtual server associations as "stale."

This is a regression from PR #2537, which added a guard for this exact scenario in _refresh_gateway_tools_resources_prompts (line 4548) but missed the same pattern in set_gateway_state (line 2503-2562).

🧩 Affected Component

Select the area of the project impacted:

• mcpgateway - API
• mcpgateway - UI (admin panel)
• mcpgateway.wrapper - stdio wrapper
• Federation or Transports
• CLI, Makefiles, or shell scripts
• Container setup (Docker/Podman/Compose)
• Other (explain below)

🔁 Steps to Reproduce

1. Register an MCP gateway with auth_type=oauth, grant_type=authorization_code
2. Log in as a regular user (not platform_admin_email), complete OAuth authorization, and fetch tools
3. Assign the tools to a virtual server
4. Wait for health check cycle (~3 minutes) — health check fails because platform_admin_email has no OAuth token for this gateway
5. Gateway goes offline (reachable=False), all tools become reachable=False
6. Now authenticate as platform_admin_email (or manually set reachable=True in DB)
7. Next health check succeeds → set_gateway_state(reachable=True) triggers re-initialization
8. All tools, resources, prompts, and virtual server associations are deleted

🤔 Expected Behavior

When set_gateway_state re-initializes an authorization_code gateway and receives an empty result (due to missing auth token), it should preserve existing tools instead of deleting them — the same behavior that _refresh_gateway_tools_resources_prompts already implements at line 4548:

📓 Logs / Error Output

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🧠 Environment Info

You can retrieve most of this from the /version endpoint.

🧩 Additional Context (optional)