[codex] admin password default

[henmohr]

What changed

• Updated the local WordPress default user password from localdev123 to admin in the submodule README.

Why

• The local SaaS workflow is being standardized around the existing admlibrecode account with password admin for faster onboarding and testing.

Impact

• The submodule documentation now matches the local root compose defaults and the reset flow used in this workspace.

Validation

• Checked the compose configuration from the repository root.
• Reset the local admlibrecode account password while testing the flow.