`docker logout docker.io` does not remove Docker Hub credentials

Look at the login and logout command implementations in the cli codebase, likely under cli/command/registry. Compare how docker.io is normalized to https://index.docker.io/v1/ during login. The fix is to ensure logout uses the same normalization. Start by reproducing the issue locally to confirm the behavior, then find the logout logic and apply the canonicalization. Verify by checking the config.json file after running the patched logout command.

Description

For Docker Hub, docker login canonicalizes docker.io to https://index.docker.io/v1/, while docker logout does not appear to apply the same canonicalization logic.

For example, when a user explicitly logs in with:

docker login docker.io

the credentials are stored in config.json under the canonical Docker Hub key:

{
  "auths": {
    "https://index.docker.io/v1/": {
      "auth": "..."
    }
  }
}

However, when the user explicitly logs out with:

docker logout docker.io

the logout logic attempts to remove credentials associated with docker.io from config.json.

Since the credentials were actually stored under https://index.docker.io/v1/, no matching docker.io entry exists, so the stored Docker Hub credentials are not removed.

In other words, docker login docker.io and docker logout docker.io use inconsistent registry host normalization for Docker Hub.

docker login docker.io and docker logout docker.io use inconsistent registry host normalization for Docker Hub.

Reproduce

1. Run docker login docker.io and authenticate successfully.
2. Check ~/.docker/config.json and verify that the credentials are stored under https://index.docker.io/v1/.
3. Run docker logout docker.io.
4. Check ~/.docker/config.json again.
5. Observe that the Docker Hub credentials under https://index.docker.io/v1/ are still present.

Expected behavior

Running docker logout docker.io should remove the Docker Hub credentials stored under https://index.docker.io/v1/.

docker version

Client:
 Version:           29.8.0
 API version:       1.56
 Go version:        go1.26.8
 Git commit:        88096ef
 Built:             Thu Sep  3 21:53:38 2026
 OS/Arch:           windows/amd64
 Context:           desktop-linux
failed to connect to the docker API at npipe:////./pipe/dockerDesktopLinuxEngine; check if the path is correct and if the daemon is running: open //./pipe/dockerDesktopLinuxEngine: The system cannot find the file specified.

docker info

Client:
 Version:    29.8.0
 Context:    desktop-linux
 Debug Mode: false
 Plugins:
  agent: Docker AI Agent Runner (Docker Inc.)
    Version:  v1.136.0
    Path:     C:\Users\yin2hao\.docker\cli-plugins\docker-agent.exe
  ai: Docker AI Agent - Ask Gordon (Docker Inc.)
    Version:  v1.31.0
    Path:     C:\Users\yin2hao\.docker\cli-plugins\docker-ai.exe
  buildx: Docker Buildx (Docker Inc.)
    Version:  v0.37.0
    Path:     C:\Users\yin2hao\.docker\cli-plugins\docker-buildx.exe
  compose: Docker Compose (Docker Inc.)
    Version:  v5.5.1
    Path:     C:\Users\yin2hao\.docker\cli-plugins\docker-compose.exe
  debug: Get a shell into any image or container (Docker Inc.)
    Version:  0.0.47
    Path:     C:\Users\yin2hao\.docker\cli-plugins\docker-debug.exe
  desktop: Docker Desktop commands (Docker Inc.)
    Version:  v0.4.4
    Path:     C:\Users\yin2hao\.docker\cli-plugins\docker-desktop.exe
  dhi: CLI for managing Docker Hardened Images (Docker Inc.)
    Version:  v0.0.7
    Path:     C:\Users\yin2hao\.docker\cli-plugins\docker-dhi.exe
  extension: Manages Docker extensions (Docker Inc.)
    Version:  v0.2.31
    Path:     C:\Users\yin2hao\.docker\cli-plugins\docker-extension.exe
  init: Creates Docker-related starter files for your project (Docker Inc.)
    Version:  v1.4.0
    Path:     C:\Users\yin2hao\.docker\cli-plugins\docker-init.exe
  mcp: Docker MCP Plugin (Docker Inc.)
    Version:  v0.43.3
    Path:     C:\Users\yin2hao\.docker\cli-plugins\docker-mcp.exe
  model: Docker Model Runner (Docker Inc.)
    Version:  v1.2.6
    Path:     C:\Users\yin2hao\.docker\cli-plugins\docker-model.exe
  offload: Docker Offload (Docker Inc.)
    Version:  v0.6.17
    Path:     C:\Users\yin2hao\.docker\cli-plugins\docker-offload.exe
  pass: Docker Pass Secrets Manager Plugin (beta) (Docker Inc.)
    Version:  v0.2.2
    Path:     C:\Users\yin2hao\.docker\cli-plugins\docker-pass.exe
  sandbox: "docker sandbox" is deprecated, use Docker Sandboxes instead (Docker Inc.)
    Version:  v0.13.0
    Path:     C:\Users\yin2hao\.docker\cli-plugins\docker-sandbox.exe
  scout: Docker Scout (Docker Inc.)
    Version:  v1.24.0
    Path:     C:\Users\yin2hao\.docker\cli-plugins\docker-scout.exe

Server:
failed to connect to the docker API at npipe:////./pipe/dockerDesktopLinuxEngine; check if the path is correct and if the daemon is running: open //./pipe/dockerDesktopLinuxEngine: The system cannot find the file specified.

Additional Info

No response