fbui v0.5.0

Added

• fbui-bare timers: Timers<M> — send, send_after, send_every,
  cancelled through a Timer handle — the no_std counterpart of
  fbui::Proxy's timers (fixed-delay repeats; dropping a handle detaches).
  The app gets the handle in the new App::on_start (default: no-op, so
  existing apps are unchanged); board code gets one from Runner::timers.
  Deadlines feed Runner::next_deadline, so Board::wait sleeps exactly
  until the next timer and idle still costs nothing. Timers armed before the
  runner has seen the clock count from its first reading.
• fbui-bare rotation: Runner::with_rotation / set_rotation (also at
  run time) turn the UI on a sideways- or upside-down-mounted panel through
  the existing copy-out rotation; input stays in panel coordinates and is
  mapped back, and Framebuffer::flush gets panel-space rects.
  fbui_bare::Rotation re-exports fbui_render::Rotation.
• fbui-bare RGB565 dithering: an Rgb565 framebuffer now gets the
  ordered (4×4 Bayer) dithered copy-out by default, as the Linux runner
  already does, so gradients don't band on 16-bit panels. This changes what
  existing RGB565 boards show (32-bit ones are unaffected);
  Runner::set_dither(false) restores the plain truncation.
• Banded rendering (NOSTD.md §6.1): Runner::new_banded(app, info, scale, band_rows) paints through a shadow a few rows tall instead of a
  whole-screen one, copying each band to the framebuffer as it is drawn
  (Surface::banded, Surface::paint_banded, Ui::paint_banded,
  Ui::request_full_paint). A 320×240 UI's peak heap drops from 800 KiB to
  161 KiB with static fonts and 16-row bands. Output is byte-identical to a
  whole-screen paint — pinned by fbui-render/tests/banded.rs and
  fbui-widgets/tests/banded.rs — except bilinear-scaled images (±1 level).
  tiny-skia's hairline rasterizer is vendored (fbui-render/src/hairline/,
  BSD-3) so hairlines stay exact across band edges.
• Bitmap fonts (NOSTD.md §6.2, fbui_render::text::bitmap): text
  with no shaping engine or rasterizer at run time. .fbf files hold glyphs
  pre-rasterized at fixed sizes (4-bit coverage, read in place, validated
  without panics); FontContext::with_bitmap_fonts, add_bitmap_font,
  BitmapFont, BitmapFontWriter, and fbui_bare::App::bitmap_fonts. The
  make_bitmap_font example generates them from any TTF/OTF;
  bundled-bitmap-font ships Inter at 12/16/20/24 px (Latin-1, 75 KB). Every
  widget works on them. The 320×240 counter UI drops to 45 KiB live / 68 KiB
  peak heap, and its firmware from 1.78 MiB to 0.66 MiB of flash with
  outline-text off. No kerning or shaping, fixed sizes, whole-pixel glyph
  positions.
• outline-text feature (default on in fbui-render, fbui-widgets and
  fbui-bare): cosmic-text and swash are now optional. FontContext::set_scale
  (called by Ui) lets bitmap fonts choose their size in device pixels.
• Fonts used in place: FontContext::with_static_fonts /
  load_static_font and fbui_bare::App::static_fonts take &'static
  font data without copying it into the heap (~300 KiB for Inter).
  FontContext::with_default_font now uses the bundled font in place too —
  on Linux as well. The doc viewer passes its compiled-in font this way.
• Runner::run — the main loop on a runner you configured; fbui_bare::run
  is now shorthand for Runner::new(..).run(..).
• fbui-bare/tests/runner.rs: direct tests of the bare runner — copy-out
  and padded stride, idle, invalidate, key and scaled pointer input,
  rotation (pixels and input for every quarter turn), RGB565 dithering,
  and timers.

Fixed

• ProgressBar, Slider and TextInput no longer stretch vertically in a
  column with free space. They set flex_grow to fill a row, but in a column
  it grew them in height: a counter screen's progress bar was laid out
  296×139 instead of 296×8. They now cap their height at their control
  height (max_size), keeping the row behaviour. Found while tracing a 41 KB
  first-frame allocation, which was the stretched bar's coverage mask.

Changed

• Breaking for default-features = false users of fbui-render /
  fbui-widgets / fbui-bare: outline text is now the outline-text
  feature. A dependent that turns default features off must add it to keep
  TTF/OTF text (FontContext::with_fonts and friends); without it only
  bitmap fonts are available. Default builds are unchanged.
• Painter no longer clones the clip mask (a full surface-sized buffer) for
  every primitive drawn under a clip; peak heap while painting a clipped
  region drops by one mask (75 KiB at 320×240). Output is unchanged.
• fbui-render's license expression is now
  (MIT OR Apache-2.0) AND BSD-3-Clause AND OFL-1.1: the crate's own code
  is unchanged in license, but it ships the vendored tiny-skia hairline
  rasterizer (BSD-3-Clause) and the Inter font files (OFL-1.1), whose
  license texts are included in the package.