chore: remove dead functions — 1 function removed (#30843)

Remove validatePiEngineRequirements which is only reachable from
CompileToYAML, itself unreachable from any production entry point.
Also remove its exclusive test file pi_validation_test.go and the
dead call site in compiler_string_api.go.

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: github-actions[bot]

pkg/workflow/compiler_string_api.go

@@ -145,11 +145,6 @@ func (c *Compiler) ParseWorkflowString(content string, virtualPath string) (*Wor
 		return nil, fmt.Errorf("%s: %w", cleanPath, err)
 	}
 
-	// Validate Pi engine requirements (gh-proxy + cli-proxy).
-	if err := c.validatePiEngineRequirements(workflowData); err != nil {
-		return nil, fmt.Errorf("%s: %w", cleanPath, err)
-	}
-
 	// Validate GitHub tool configuration
 	if err := validateGitHubToolConfig(workflowData.ParsedTools, workflowData.Name); err != nil {
 		return nil, fmt.Errorf("%s: %w", cleanPath, err)

pkg/workflow/engine_validation.go

@@ -365,41 +365,6 @@ func (c *Compiler) validateSingleEngineSpecification(mainEngineSetting string, i
 	return "", fmt.Errorf("invalid engine configuration in included file, missing or invalid 'id' field. Expected string, object with 'id' field, or inline definition with 'runtime.id'.\n\nExample (string):\nengine: copilot\n\nExample (object with id):\nengine:\n  id: copilot\n  model: gpt-4\n\nExample (inline runtime definition):\nengine:\n  runtime:\n    id: codex\n\nSee: %s", constants.DocsEnginesURL)
 }
 
-// validatePiEngineRequirements validates that workflows using the Pi engine have
-// the required configuration: gh-proxy mode and CLI proxy must both be enabled.
-//
-// Pi's API integration requires:
-//   - tools.github.mode: gh-proxy — the pre-authenticated gh CLI must be available
-//   - tools.cli-proxy: true — MCP servers must be mounted as CLI tools on PATH
-//
-// This requirement cannot be relaxed; the Pi engine communicates with GitHub via
-// the gh CLI rather than the GitHub MCP protocol.
-func (c *Compiler) validatePiEngineRequirements(workflowData *WorkflowData) error {
-	if workflowData.EngineConfig == nil || workflowData.EngineConfig.ID != string(constants.PiEngine) {
-		return nil
-	}
-
-	engineValidationLog.Print("Validating Pi engine requirements: gh-proxy and cli-proxy")
-
-	ghProxyEnabled := isGitHubCLIModeEnabled(workflowData)
-	cliProxyEnabled := workflowData.ParsedTools != nil && workflowData.ParsedTools.CLIProxy
-
-	if !ghProxyEnabled && !cliProxyEnabled {
-		return fmt.Errorf("the Pi engine requires gh-proxy and CLI proxy to be enabled.\n\nAdd the following to your workflow frontmatter:\n\n  tools:\n    github:\n      mode: gh-proxy\n    cli-proxy: true\n\nSee: %s", constants.DocsEnginesURL)
-	}
-
-	if !ghProxyEnabled {
-		return fmt.Errorf("the Pi engine requires gh-proxy to be enabled.\n\nAdd the following to your workflow frontmatter:\n\n  tools:\n    github:\n      mode: gh-proxy\n\nSee: %s", constants.DocsEnginesURL)
-	}
-
-	if !cliProxyEnabled {
-		return fmt.Errorf("the Pi engine requires CLI proxy to be enabled.\n\nAdd the following to your workflow frontmatter:\n\n  tools:\n    cli-proxy: true\n\nSee: %s", constants.DocsEnginesURL)
-	}
-
-	engineValidationLog.Print("Pi engine requirements satisfied: gh-proxy and cli-proxy are enabled")
-	return nil
-}
-
 // EngineHasValidateSecretStep checks if the engine provides a validate-secret step.
 // This is used to determine whether the secret_verification_result job output should be added.
 //