chore: resolve golangci-lint v2.12.1 goconst findings

[Joibel]

Summary

• Resolve all 50 goconst violations reported by golangci-lint v2.12.1 (the version pinned in .github/workflows/ci.yml).
• Reuse existing constants (KindWorkflow, KindWorkflowTemplate, KindClusterWorkflowTemplate, KindCronWorkflow, OutputFormatJSON, OutputFormatYAML, PhasePending) and introduce new ones for repeated strings: workflow phases (PhaseRunning, PhaseSucceeded, PhaseFailed, PhaseUnknown), template types (templateType*), graph node statuses (nodeStatus*), JSON resource keys (jsonKey*, mimeTypeJSON), the conventional Argo container name (containerMain), and a couple of error/IO strings in the prompts package.
• Rename three slog field names from "default" to "fallback" so the literal isn't reused with two different meanings (and the namespace use-case gets a proper defaultNamespace constant).

Test plan

• make lint (with golangci-lint v2.12.1) — 0 issues
• make test — all packages pass with race detection
• make vet — clean
• make fmt — no diffs

Summary by CodeRabbit

• New Features

  • Added parameter override capability when submitting workflows.

• Improvements

  • Enhanced error diagnostics for failed workflows with improved pattern detection.
  • Improved log handling with UTF-8 safe truncation to prevent corruption.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

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Review profile: ASSERTIVE

Plan: Pro

Run ID: eb172eb7-a1a3-4899-ba10-04c0e0625a6a

📥 Commits

Reviewing files that changed from the base of the PR and between 4b5ad62 and 3989163.

📒 Files selected for processing (20)

• pkg/argo/config.go
• pkg/prompts/why_did_this_fail.go
• pkg/resources/cluster.go
• pkg/tools/convert_workflow.go
• pkg/tools/create_cluster_workflow_template.go
• pkg/tools/create_cron_workflow.go
• pkg/tools/create_workflow_template.go
• pkg/tools/get_workflow_template.go
• pkg/tools/lint_cluster_workflow_template.go
• pkg/tools/lint_cron_workflow.go
• pkg/tools/lint_workflow.go
• pkg/tools/lint_workflow_template.go
• pkg/tools/list_workflows.go
• pkg/tools/logs_workflow.go
• pkg/tools/render_manifest_graph.go
• pkg/tools/render_workflow_graph.go
• pkg/tools/retry_workflow.go
• pkg/tools/submit_workflow.go
• pkg/tools/wait_workflow.go
• pkg/tools/watch_workflow.go

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Walkthrough

This pull request standardizes string literals across the codebase by introducing internal constants for configuration values, MIME types, JSON keys, workflow phases, manifest kinds, and node/template types. It also adds error pattern tracking capabilities and UTF-8-safe log truncation to enhance workflow diagnostics.

Changes

Constants and Configuration Standardization

Layer / File(s)	Summary
Configuration & Logging pkg/argo/config.go	Introduces defaultNamespace constant and renames error log field from "default" to "fallback" across three environment-variable parsing paths.
Resource MIME Types & JSON Keys pkg/resources/cluster.go	Defines constants for MIME type (mimeTypeJSON) and JSON object keys (jsonKeyName, jsonKeyNamespace, jsonKeyCount), then applies them throughout cluster resource endpoints and content builders.
Manifest Kind Validation pkg/tools/create_cluster_workflow_template.go, pkg/tools/create_cron_workflow.go, pkg/tools/create_workflow_template.go, pkg/tools/lint_cluster_workflow_template.go, pkg/tools/lint_cron_workflow.go, pkg/tools/lint_workflow.go, pkg/tools/lint_workflow_template.go	Replace hardcoded manifest kind strings ("Workflow", "CronWorkflow", "WorkflowTemplate", "ClusterWorkflowTemplate") with corresponding kind constants in validation checks.
Workflow Phase Constants & Utilities pkg/tools/submit_workflow.go, pkg/tools/retry_workflow.go, pkg/tools/wait_workflow.go, pkg/tools/watch_workflow.go, pkg/tools/list_workflows.go	Expand workflow phase constants (PhasePending, PhaseRunning, PhaseSucceeded, PhaseFailed, PhaseUnknown) and apply them throughout phase assignments and mappings. Add applyParameterOverrides helper to submit handler.
Output Format Constants pkg/tools/convert_workflow.go	Replace "json" and "yaml" string literals with OutputFormatJSON and OutputFormatYAML constants in manifest serialization.
Template Type Inference pkg/tools/get_workflow_template.go, pkg/tools/render_manifest_graph.go	Introduce constants for template types (Container, Script, DAG, Steps, Resource, Suspend, HTTP, Plugin, Unknown) and expand determineTemplateType / getTemplateType to return these constants.
Node & Graph Rendering pkg/tools/render_manifest_graph.go, pkg/tools/render_workflow_graph.go	Add constants for node status class names (nodeStatusSucceeded, nodeStatusFailed, etc.), node types (nodeTypeDAGTask, nodeTypeStep), and default colors; update graph rendering logic to use these constants.
Logging Defaults pkg/tools/logs_workflow.go	Introduce containerMain constant and apply it as default container reference.
Error Pattern Tracking & Diagnostics pkg/prompts/why_did_this_fail.go	Add ErrorPattern field to failed node diagnostics; introduce constants for I/O type parameter naming (ioTypeParameter) and image-pull error pattern (errorPatternImagePullBackOff); add truncateStringBytes helper for UTF-8-safe log truncation.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Poem

🐰 A refactoring most grand,
Where strings now bow to constant's command,
With phases, types, and JSON keys made clear,
The code's intent shines ever bright here!
UTF-8 whispers, patterns emerge—
A codebase refined, its quality surge! ✨

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately and concisely describes the main objective of the pull request: resolving golangci-lint goconst findings by replacing string literals with named constants.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/golangci-lint-goconst-issues

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