Run upstream tektoncd/pipeline PipelineRun examples through mallet

[vdemeester]

Goal

Systematically run the ~35 PipelineRun examples from tektoncd/pipeline through mallet, track pass/fail, and fix the gaps discovered.

Why

The current test suite uses 13 simple in-repo examples. Running upstream's own examples is the fastest way to validate real-world feature coverage and discover missing functionality.

Candidate examples (non-exhaustive)

• pipelinerun-with-params.yaml
• pipelinerun-with-when-expressions.yaml
• pipelinerun-with-final-tasks.yaml
• pipelinerun-with-final-results.yaml
• pipelinerun-task-execution-status.yaml
• pipelinerun-results.yaml / pipelinerun-results-with-params.yaml
• pipelinerun-array-results-substitution.yaml
• pipeline-object-param-and-result.yaml
• propagating_params_implicit_parameters.yaml / propagating_params_in_pipeline.yaml
• propagating-workspaces.yaml / propagating-workspaces-in-pipelines.yaml
• optional-workspaces.yaml / using-optional-workspaces-in-when-expressions.yaml
• workspace-from-volumeclaimtemplate.yaml
• using_context_variables.yaml
• ignore-step-error.yaml
• mapping-workspaces.yaml
• stepaction-params.yaml

Known gaps (tracked as separate issues)

Feature	Issue	Upstream examples needing it
$(tasks.X.status) in when expressions	#42	pipelinerun-task-execution-status, finally tasks
$(tasks.status) aggregate status	#42	pipelinerun-task-execution-status
securityContext (runAsUser)	#43	step-script, many taskruns
Propagating params (implicit)	#44	propagating_params_*
Propagating workspaces (implicit)	#45	propagating-workspaces*
Optional workspaces	#46	optional-workspaces*

Acceptance Criteria

• Track results in a compatibility matrix (example name, pass/fail, blocking feature)
• Fix blocking gaps to achieve ≥80% pass rate on self-contained upstream examples
• Add passing upstream examples to CI as regression tests
• Document known limitations for examples that can't work locally (e.g., PVC-dependent)

Jira: SRVKP-11415