Align repository testing with the accepted ModuLix test architecture ADR

[litroc]

Context

Lightning IT accepted the ModuLix test architecture ADR: https://wiki.cloud.l-it.io/wiki/spaces/LIT/pages/2886566105

Component test logic stays with source code; Static, Unit, and Tiny execute locally; Heavy and cross-repository Application Acceptance execution is orchestrated exclusively by modulix-validation.

Scope

• Inventory and classify tests as Static, Unit, Tiny, Heavy, or Application Acceptance.
• Confirm local workflows execute only Static, Unit, and Tiny.
• If Heavy behavior exists, keep assertions here but delegate execution to the SHA-pinned central workflow.
• Remove duplicate Heavy runner, secret, provisioning, and cleanup configuration.
• Document an explicit “no Heavy tests” result where applicable.

Acceptance criteria

• Test inventory and profile classification are documented.
• No independent Heavy or cross-repository Acceptance execution remains.
• Central workflow references are pinned by full commit SHA.
• Required jobs cannot pass by being skipped.
• Documentation references ADR 2886566105.