2.0.0

The first stable 2.0 release. This is a ground-up rewrite of the rendering
pipeline with a new Generator entry point, composable backgrounds, accurate
font metrics, and multi-language text support. It consolidates everything from
2.0.0-beta.1 through 2.0.0-beta.4.

Upgrading from 1.x? This release is not backward compatible — see
Breaking Changes below. Install with composer require yilanboy/preview:^2.0.

💥 Breaking Changes

• Minimum PHP is now ^8.4 (was ^8.2).
• Image\Builder is replaced by Generator as the main entry point — an API
  rename, not backward compatible.
• Color\Converter is replaced by a top-level ColorConverter with static
  methods; dependency injection removed.
• The backgroundColor shortcut is removed. Backgrounds are now configured
  via dedicated background classes (Solid, Gradient, Image).
• Background interfaces moved into a Contracts namespace (Contracts\Background).
• Text handling reworked around a new TextBlock value object and an internal
  layout engine.

✨ Added

• Composable backgrounds (Yilanboy\Preview\Canvas):
  • Solid — a flat color.
  • Gradient — two-color interpolation with a GradientDirection enum
    (Vertical, Horizontal, Diagonal).
  • Image — a bitmap background with an ImageFit enum (Cover, Contain,
    Stretch, Tile), configurable opacity, and a tint color.
• TextBlock value object (immutable, final readonly) for title and
  description text, with Font, FontSize, Alignment, LineHeight, and
  Position enums. Title and description stack without overlapping.
• Custom TrueType fonts — pass a .ttf file path, validated on construction
  (OpenType / non-TTF files are rejected).
• Multi-language text rendering for Traditional Chinese, Simplified Chinese,
  and Japanese, with appropriate word/character wrapping.
• Custom canvas sizes and font sizes — Generator::dimensions(int, int) and a
  custom integer pixel FontSize, both validated (InvalidInput below 1).
• Size, Margin, and Format enums for canvas presets and output encoding.
• Typed exceptions in a new Exceptions namespace: InvalidInput and
  RenderFailure, both implementing the PreviewException marker interface.
  Backward compatible — they still extend the SPL exceptions the library threw
  before, so existing catch blocks keep working.
• Color validation enforced at construction across all color-accepting types
  via ColorConverter::isValidColor() (named colors or hex).

🛠 Improved & Fixed

• Accurate line height derived directly from the font's head/hhea sfnt
  tables (via a new LineMetrics value object) instead of glyph bounding-box
  probing.
• More robust font parsing — sfnt tables are validated and binary unpacking
  errors are handled gracefully, throwing RenderFailure on corrupt font files.
• Faster rendering — text lines are measured once during wrapping and reused
  at placement; Image backgrounds decode the source file once and cache the
  bitmap.

Full Changelog: 1.0.1...2.0.0