Add JSON output to `test` command

[josecelano]

Overview

Add JSON output format support to the test command (roadmap task 12.8). This is part of Phase 2 of the JSON output epic (#348), which aims to implement JSON output for all remaining commands so that JSON can eventually become the default output format.

The test command currently only outputs human-readable text progress messages and DNS warnings. This task adds a machine-readable JSON alternative that automation workflows, CI/CD pipelines, and AI agents can parse programmatically.

Key difference from other commands: The test command does not transition environment state. It loads the current environment (any state), validates running services, and returns a TestResult containing pass/fail status and advisory DNS warnings. The JSON output schema reflects this test-result nature rather than the environment-state pattern used by other commands.

Specification

See detailed specification: docs/issues/380-add-json-output-to-test-command.md

🏗️ Architecture Requirements

DDD Layer: Presentation
Module Path: src/presentation/views/commands/test/
Pattern: Strategy Pattern for rendering

Module Structure Requirements

• Follow DDD layer separation (see docs/codebase-architecture.md)
• Respect dependency flow rules (dependencies flow toward domain)
• Use appropriate module organization (see docs/contributing/module-organization.md)

Architectural Constraints

• No business logic in presentation layer
• Error handling follows project conventions (see docs/contributing/error-handling.md)
• Testing strategy aligns with layer responsibilities

Anti-Patterns to Avoid

• ❌ Mixing rendering concerns in the controller
• ❌ Adding business logic to view structs
• ❌ Using println!/eprintln! instead of UserOutput

Implementation Plan

Step 1: Create View Module Structure

• Create src/presentation/views/commands/test/ with mod.rs, view_data/, views/

Step 2: Extend TestResult (Application Layer)

• Add instance_ip: IpAddr field to TestResult
• Update constructors and existing tests

Step 3: Implement DTO

• Implement TestResultData and DnsWarningData structs
• Implement TestResultData::new() constructor

Step 4: Implement Views

• Implement JsonView::render() with inline error handling
• Implement TextView::render() with formatted text output

Step 5: Update Controller

• Add output_format: OutputFormat parameter to execute()
• Update fixture_infrastructure() to return TestResult
• Implement Strategy Pattern in complete_workflow()

Step 6: Update Router

• Pass output_format from context to controller

Step 7: Add Tests

• Unit tests for DTO, JsonView, and TextView

Step 8: Documentation

• Update docs/user-guide/commands/test.md with JSON output examples
• Correct existing inaccuracies in user docs (test categories, state validation, exit codes, execution flow don't match actual implementation)

Acceptance Criteria

Note for Contributors: These criteria define what the PR reviewer will check. Use this as your pre-review checklist before submitting the PR to minimize back-and-forth iterations.

Quality Checks:

• Pre-commit checks pass: ./scripts/pre-commit.sh

Task-Specific Criteria:

• test command accepts --output-format json flag
• JSON output includes environment_name, instance_ip, result, and dns_warnings fields
• dns_warnings array correctly serializes warning details (domain, expected_ip, issue)
• Text output preserves current UX behavior
• Unit tests cover DTO conversion, JsonView, and TextView (with and without DNS warnings)
• User documentation updated and corrected

Related

• Parent: EPIC: Add JSON output format support #348 (EPIC: Add JSON output format support)
• Roadmap: Roadmap #1 (Project Roadmap)
• Specification: docs/issues/380-add-json-output-to-test-command.md