template: pin comparevi consumer default to stable

[svelderrainruiz]

Summary

• replace the template's default compare-vi-cli-action consumer pin with the latest supported stable tag v0.6.3
• update the smoke workflow, render helper default, cookiecutter prompt, and consumer-facing docs together so the template no longer defaults to the RC pin
• preserve the downstream proving flow while clearing the current required onboarding failure

Why

A fresh onboarding run from compare-vi-cli-action against LabVIEW-Community-CI-CD/LabviewGitHubCiTemplate reported:

• status: fail
• required failures: 1
• warnings: 2
• current consumer ref: v0.6.4-rc.2

The only required failure was certified-reference-pinned: the template consumed an RC tag instead of a certified stable immutable reference.

Validation

• git diff --check
• rg -n 'v0\\.6\\.4-rc\\.2|v0\\.6\\.3' . -g '!**/archive/**'