test: tighten module run source resolution coverage

[edmundmiller]

Summary

• refactor CmdModuleRun to expose a small resolveModuleSource() seam for focused tests
• replace brittle full-cmd.run() specs with source-resolution specs
• add data-driven and interaction-based Spock coverage for local-vs-registry dispatch

Why

This PR is stacked on top of #7057 and focuses only on the tests we want to see for local nextflow module run behavior.

In particular, it proves:

• local module directories resolve to main.nf
• local module files resolve directly
• local sources dispatch to the local resolver and bypass remote resolution
• registry-style sources dispatch to the remote resolver and bypass local resolution
• error cases still raise AbortOperationException

Test Plan

• ./gradlew :nextflow:test --tests 'nextflow.cli.module.CmdModuleRunTest'

Depends on:

• Allow module run to run modules with local path #7057