Structurally refactor Site class into Facade and separate Managers

[gerteck]

What is the purpose of this pull request?

• Documentation update
• Bug fix
• Feature addition or enhancement
• Code maintenance
• DevOps
• Improve developer experience
• Others, please explain:

Overview of changes:

Closes #2774
Closes #1756

Anything you'd like to highlight/discuss:
The Site class had become a "God Class" with many responsibilities, making it hard to maintain and test.

This PR refactors and decouples the monolithic Site god class class into a Facade provided by Site/index.ts. It delegates responsibilities to four newly created manager classes (SiteAssetsManager, SitePagesManager, SiteDeployManager, and SiteGenerationManager), which are currently defined within the same file.

• Organize classes in Site/index.ts for git history, tracking before evict to separate files.
• Extract responsibilities into dedicated manager classes
  • SiteAssetsManager: Asset handling (copying, building, removing).
    • Responsibility: Copying fonts, CSS, JS bundles, and bootstrap themes to the output directory. Handling ignore rules for assets.
  • SitePagesManager: Page collection and dependency management.
    • Responsibility: Collecting addressable pages from globs, creating Page objects, parsing frontmatter for configuration, and mapping URLs.
  • SiteDeployManager: GH Pages and others deployment logic.
    • Responsiblity: Pushing the artifacts in _site to a remote git branch (GitHub Pages).
  • SiteGenerationManager: Core build orchestration (generate, rebuild, lazy loading).
    • Responsibility: Orchestrating the build process (generate, buildSourceFiles), managing lazy loading logic, re-building affected pages, and writing site data.

• Refactor Site class as Facade, delegate logic to underlying managers
• Maintain public API compatibility for now.

• Separate testcases for better maintainability.

Additionally, using Site class as a Facade now enables us to hide some of the methods that are not used and not overexpose internal methods. Instead, we can easily see the key interfaces the core package (Site object) exposes for consumers to use.

• Previously, the Site class exposed numerous internal methods, allowing external manipulation of internal state and obscuring the actual public API. This change reduces the surface area of the Site class, making the core package easier to maintain and consume.

Testing instructions:

npm run test

Proposed commit message: (wrap lines at 72 characters)

Rebase and Merge

to preserve commit history as much as possible

---

Checklist: ☑️

• Updated the documentation for feature additions and enhancements
• Added tests for bug fixes or features
• Linked all related issues
• No unrelated changes

---

Reviewer checklist:

Indicate the SEMVER impact of the PR:

• Major (when you make incompatible API changes)
• Minor (when you add functionality in a backward compatible manner)
• Patch (when you make backward compatible bug fixes)

At the end of the review, please label the PR with the appropriate label: r.Major, r.Minor, r.Patch.

Breaking change release note preparation (if applicable):

• To be included in the release note for any feature that is made obsolete/breaking

Give a brief explanation note about:

• what was the old feature that was made obsolete
• any replacement feature (if any), and
• how the author should modify his website to migrate from the old feature to the replacement feature (if possible).

[codecov]

Codecov Report

❌ Patch coverage is 43.24324% with 462 lines in your changes missing coverage. Please review.
✅ Project coverage is 63.17%. Comparing base (2400af3) to head (a7b2c45).

Files with missing lines	Patch %	Lines
packages/core/src/Site/SiteGenerationManager.ts	19.95%	357 Missing ⚠️
packages/core/src/Site/SiteAssetsManager.ts	54.80%	47 Missing ⚠️
packages/core/src/Site/SitePagesManager.ts	62.96%	39 Missing and 1 partial ⚠️
packages/core/src/Site/SiteDeployManager.ts	89.81%	11 Missing ⚠️
packages/core/src/Site/index.ts	82.05%	7 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2775      +/-   ##
==========================================
+ Coverage   62.30%   63.17%   +0.87%     
==========================================
  Files         130      133       +3     
  Lines        7184     7265      +81     
  Branches     1580     1512      -68     
==========================================
+ Hits         4476     4590     +114     
+ Misses       2644     2611      -33     
  Partials       64       64              

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[Copilot]

Pull request overview

This PR refactors the monolithic Site class into a facade pattern with specialized manager classes, improving code maintainability and separation of concerns without breaking the public API.

Changes:

• Introduced four new manager classes to handle distinct responsibilities: SiteAssetsManager, SitePagesManager, SiteDeployManager, and SiteGenerationManager
• Refactored the Site class as a facade that delegates to these managers while maintaining backward compatibility
• Moved constants to a centralized location and reorganized test files to match the new structure

Reviewed changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
packages/core/src/Site/index.ts	Refactored Site class as facade delegating to manager classes
packages/core/src/Site/SitePagesManager.ts	New manager handling page creation and collection logic
packages/core/src/Site/SiteGenerationManager.ts	New manager orchestrating build process and page generation
packages/core/src/Site/SiteDeployManager.ts	New manager handling deployment operations
packages/core/src/Site/SiteAssetsManager.ts	New manager handling asset operations (CSS, JS, fonts, images)
packages/core/src/Site/constants.ts	Added new constants extracted from Site class
packages/core/test/unit/Site.test.ts	Removed old monolithic test file
packages/core/test/unit/Site/Site.test.ts	New test file for refactored Site facade
packages/core/test/unit/Site/SitePagesManager.test.ts	New test file for SitePagesManager
packages/core/test/unit/Site/SiteGenerationManager.test.ts	New test file for SiteGenerationManager
packages/core/test/unit/Site/SiteDeployManager.test.ts	New test file for SiteDeployManager
packages/core/test/unit/Site/SiteAssetsManager.test.ts	New test file for SiteAssetsManager

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

Pull request overview

Copilot reviewed 12 out of 12 changed files in this pull request and generated 5 comments.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.