Run required validation gates

Run only the gates required by the change class and report results as a concise gate recap.

Procedure

1. Classify the change as one of: docs-only, terraform-module, example-terraform, ci-workflow, mixed.
2. For mixed, run the union of gates for all relevant classes.
3. Execute canonical commands from the validation-gates rule.
4. For Terraform plan commands using -detailed-exitcode:
   • 0 = no diff (PASS)
   • 2 = diff exists (PASS only if diff matches intended changes)
   • any other code = FAIL
5. If a gate cannot run, record a waiver containing skipped gate, reason, residual risk, and acceptance context.
6. End with a compact gate summary listing command scope, result, and waivers.

Reporting format

Use concise output:

• Gates: terraform fmt -check -recursive passed; terraform -chdir=. validate passed; terraform -chdir=examples/test_app plan -detailed-exitcode=2 reviewed (expected diff).
• Gates: links checked; markdown lint not run (waived: tooling unavailable, low risk).