feat(plugins/ci-cd) - v1.4.6 build and plugin fixes

[medevod]

Summary

This PR modernizes the build and distribution pipeline, refactors the vanilla TypeScript plugins for SSR safety and accessibility, establishes a unified multi-framework architecture guide, and updates project CI/CD workflows and roadmaps.

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Tasks Completed

🏗️ Architecture & Documentation

• Add Multi-Framework Architecture Specification (ARCHITECTURE.md)
  • Define core architectural principles and separation of concerns (CSS core vs. framework adapters).
  • Specify component API contracts, lifecycle states, and ARIA attributes.
  • Document framework adapter strategy (React, Vue, Svelte, Angular, Solid) and headless state logic.
  • Define CSS custom property contract, theme engine specification, and SSR/SSG compatibility guidelines.
• Establish Roadmap & Milestones (ROADMAP.md)
  • Define phased evolutionary path (Core Stabilization $\rightarrow$ Multi-Framework Adapters $\rightarrow$ Design Tokens $\rightarrow$ Ecosystem).

📦 Build, Packaging & Distribution

• Modernize Package Exports & Module Definitions (package.json)
  • Add dual ESM and CJS entry points with conditional exports map (., ./css, ./dist/*).
  • Configure TypeScript declaration emission to dist/types/mgplus.d.ts.
  • Add CDN entries (unpkg, jsdelivr) and style path definitions.
  • Remove duplicate/obsolete .stylelintrc.* config files in favor of unified configurations.
  • Configure dedicated TypeScript library build config (tsconfig.lib.json).
• Tooling & Package Manager Migration
  • Migrate dependency lockfile and scripts to standard npm workflow (package-lock.json).
  • Add NPM scripts for typecheck, lint:css, lint:js, and unified test.

🧩 Plugin Refactoring & Enhancements

• SSR Guarding & Idempotent Initialization
  • Add typeof document === "undefined" checks to prevent SSR crashes in Node/Next.js/Nuxt environments.
  • Add dataset initialization flags (data-mg-*-initialized) across plugins to prevent duplicate event listener bindings.
• Accessibility (a11y) & DOM Improvements
  • Collapse (src/plugins/mgCollapse.ts): Add aria-expanded toggling and event target resolution via .closest().
  • Tabs (src/plugins/mgTabs.ts): Add role="tab", aria-selected, aria-controls, and aria-hidden management.
  • Dropdown (src/plugins/mgDropdown.ts): Add outside click handler, aria-expanded, and keyboard escape dismiss support.
  • Modal (src/plugins/mgModal.ts): Add backdrop click handling and multi-trigger / multi-close button support.
  • Navigation (src/plugins/mgNav.ts): Scope active state toggling strictly to parent container items.
  • Dark Mode (src/plugins/mgDarkMode.ts): Improve theme persistence and auto system preference detection (prefers-color-scheme).
  • Init Entry (src/plugins/mgplus.ts): Provide safe single entry point mgplus.init() and export individual register functions.
• Demo Cleanup (src/demo/main.ts)
  • Refactor color picker demo, theme previewer, and component playground.

🤖 CI/CD Workflows

• Update GitHub Actions (.github/workflows/)
  • Upgrade Node.js runner to Node 20.x across workflows.
  • Upgrade action versions to actions/checkout@v4 and actions/setup-node@v4.
  • Fix action metadata typo and switch release step to npm publish --access public.

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Verification & Testing

• npm run typecheck (TypeScript typecheck passed with no diagnostics errors)
• npm run build:lib (ESM, UMD bundles and .d.ts type declarations generated in dist/)
• npm run build:demo (Demo application build verified)