Add bundle release date command options

[lcawl]

Relates to #3030
This PR is a follow-up to #3066

Overview

This PR implements comprehensive release date automation for changelog bundles, focusing on CI/CD workflows while maintaining flexibility for different use cases. The feature allows release dates to be automatically populated and conditionally rendered based on configuration.

Key Features

🚀 Automatic Release Date Population

• Auto-population: Bundles automatically get today's date (UTC) when no explicit date is provided
• GitHub Integration: changelog gh-release automatically uses the GitHub release published_at date
• CLI Override: --release-date YYYY-MM-DD flag for explicit date specification
• Preservation: Existing release dates in bundle YAML files are preserved during re-bundling

🎛️ Configurable Rendering Control

• Bundle-level control: bundle.show_release_dates configuration (defaults to false)
• Profile-level override: bundle.profiles.<name>.show_release_dates for per-profile customization
• Conditional rendering: Release dates only appear in output when both enabled and present
• CLI flag: --no-release-date to explicitly suppress date population

🔧 Profile Mode Enhancement

• Seamless integration: Profile and option modes of changelog bundle behave identically
• Configuration inheritance: Profiles inherit bundle-level show_release_dates setting
• No manual editing: Eliminates need to manually update config files before releases

Major Files Changed

Configuration & Domain Models

• BundleConfiguration.cs - Added ShowReleaseDates property (default: false)
• Bundle.cs - Added ShowReleaseDates property to domain model
• ChangelogConfigurationYaml.cs - YAML serialization support
• ChangelogConfigurationLoader.cs - Configuration parsing logic

Core Services

• ChangelogBundlingService.cs - Auto-population and profile resolution logic
• GitHubReleaseChangelogService.cs - GitHub published_at date integration
• GitHubReleaseService.cs - Extended GitHub API response parsing

Rendering Engine

• ChangelogRenderingService.cs - Bundle-level rendering control
• IndexMarkdownRenderer.cs - Conditional Markdown output
• ChangelogAsciidocRenderer.cs - Conditional AsciiDoc output
• ChangelogInlineRenderer.cs - Directive rendering updates

CLI Interface

• ChangelogCommand.cs - Added --release-date and --no-release-date flags with validation

Documentation

• Updated CLI docs (bundle.md, gh-release.md)
• Enhanced syntax documentation (changelog.md)
• Added contribution guidelines (contribute/changelog.md)
• Updated example configuration (changelog.example.yml)

Usage Examples

CLI Commands

# Auto-populate with today's date (profile mode)
changelog bundle elasticsearch-release 9.1.0

# Specify explicit release date (option mode)
changelog bundle --all --release-date 2026-04-15

# Suppress release date entirely (option mode)
changelog bundle --all --no-release-date

# GitHub release with automatic date from published_at
changelog gh-release elastic/elasticsearch v9.1.0

# GitHub release with explicit override date
changelog gh-release elasticsearch v9.1.0 --release-date 2026-04-15

Configuration

# changelog.yml
bundle:
  show_release_dates: false  # Default: don't show dates
  profiles:
    release:
      show_release_dates: true  # Override for release profile
      description: "Release {version} ({lifecycle})"

Technical Implementation

Resolution Order (ShowReleaseDates)

1. CLI flag (--no-release-date sets to false)
2. Profile-level setting (bundle.profiles.<name>.show_release_dates)
3. Bundle-level default (bundle.show_release_dates)
4. System default (false)

Resolution Order (ReleaseDate)

1. Existing bundle date (preserved during re-bundling)
2. CLI explicit date (--release-date)
3. GitHub release published_at (for gh-release command)
4. Auto-populated UTC date (when not suppressed by --no-release-date)

Rendering Logic

Release dates appear in output only when:

• ShowReleaseDates is true AND
• A ReleaseDate value is present

Backward Compatibility

• ✅ Default behavior: show_release_dates defaults to false - no impact on existing documentation
• ✅ Existing bundles: Previously created bundles continue to work unchanged
• ✅ Bundle amend: changelog bundle-amend preserves existing release date metadata
• ✅ Configuration: Optional fields - existing config files require no updates

Testing Status

• ✅ Compilation: All code compiles successfully
• ✅ Existing functionality: Maintains backward compatibility with existing release-date features
• ⚠️ New feature tests: Comprehensive tests for new ShowReleaseDates functionality should be added in follow-up work

Breaking Changes

None. All new functionality is opt-in with safe defaults.

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This implementation prioritizes CI/CD automation while providing flexible control over release date rendering, supporting both automated workflows and manual release processes.

Generative AI disclosure

1. Did you use a generative AI (GenAI) tool to assist in creating this contribution?

• Yes
• No

2. If you answered "Yes" to the previous question, please specify the tool(s) and model(s) used (e.g., Google Gemini, OpenAI ChatGPT-4, etc.).

Tool(s) and model(s) used: claude-sonnet-4