Atlassian MCP OAuth fails: callback URL mismatch (random port vs registered 33418)

Version: Copilot CLI 1.0.84-3 (tested on 1.0.83 and 1.0.84-3)
Environment: WSL Ubuntu 24.04
MCP Server: Atlassian (https://mcp.atlassian.com/v1/mcp/authv2)

Issue:
When connecting to the Atlassian MCP server via Copilot CLI, OAuth always fails with:
"The app's callback URL is invalid. Contact the app developer to fix the redirect URL in the app's settings."

Root Cause:
Copilot CLI generates a random localhost port for OAuth redirect on each auth attempt, but the GitHub Copilot CLI client metadata at https://github.com/copilot/cli/client-metadata.json only registers:

• http://127.0.0.1:33418/ (only valid callback)

Observed redirect attempts: 55096, 64611, 50069, etc.
Atlassian OAuth validation rejects these mismatched ports.

Workaround Needed:

• Either hardcode Copilot CLI to always use port 33418
• Or expose a configurable --redirect-port flag
• Or update client metadata to accept random ports within a range

Error ID: c66b2f8a-87f3-404d-9e60-41b4d023c67c

First reproduce the OAuth failure in WSL Ubuntu with the Atlassian MCP server and compare the observed random callback ports with client-metadata.json. Then inspect where Copilot CLI selects its OAuth redirect port. Done means authentication succeeds using the registered 33418 callback or a clearly supported configurable alternative.