flterm v0.0.3

Breaking

• Flutter SDK floor: requires Dart 3.12 and Flutter 3.44.

Added

• IME composition: composing text appears at the terminal cursor
  and works with platform text input.
• Sprite glyph rendering: box drawing, block elements, Braille,
  Powerline, geometric shapes, and legacy computing glyphs render
  with built-in glyphs.
• Shared render caches: TerminalScope lets multiple terminal
  views share compatible rendering resources.
• APC buffer limits: TerminalConfig.apcBufferLimit controls how
  much APC payload data the terminal accepts.

Changed

• Rendering pipeline: terminal frames share rendering caches and do
  less repeated work between frames.

Fixed

• Keyboard input: shifted printable keys and IME editing produce
  the expected terminal text.
• Rendering accuracy: erased backgrounds, cursor shape, cell
  metrics, and sprite glyphs render more consistently.