ci: Define module completion gates before NuGet prerelease

[teesofttech]

Goal

Agree the quality bar for finishing a module before publishing a NuGet prerelease and moving to the next module.

Proposed Gate

For each module:

• Public API reviewed and documented.
• Unit tests cover request construction, response parsing, auth behavior, validation, and errors.
• Integration tests cover at least one happy-path real Tableau call when credentials are available.
• Examples project includes a runnable sample for the module.
• README or docs include minimal usage.
• dotnet build, dotnet test, and dotnet pack pass.

Scope

• Add a checklist template for module completion.
• Add CI checks that support this workflow.
• Decide whether integration tests are required for publish or only required when secrets exist.

Done When

Every module issue can use the same definition of done before release.