Images: SVG and EPS export write colorized grayscale and 1-bit images in their fill color

SVG export ignored an image's colorize paint and wrote the image's own
black, white and gray pixels. EPS export flattened every colorized image
into a process-color raster, so a spot color lost its plate. Both now
write the image in the fill color, with the coverage the canvas and PDF
export use (darkness times alpha), so white and transparent pixels take
no color.

- SVG writes a coverage PNG as a mask over a rectangle in the color,
  shared between repeated images while each keeps its own color. Linked
  mode writes the coverage PNG as a file, and SVG Tiny 1.2 writes a PNG
  in the color. A colorized image whose pixels are missing, or whose
  grayscale pixels can't be decoded, is left out with a warning.
- EPS writes fully covered or uncovered pixels as an imagemask in the
  color's process or Separation ink (Registration on every plate), and a
  grayscale image as ink samples scaled by coverage. Level 3 masks its
  uncovered pixels out and Level 2 writes them white; gray midtones are
  written over white, with the existing warnings.
- EPS flattening no longer counts a solid colorize paint on a grayscale
  or 1-bit image as transparency by itself. Opacity, blending modes,
  opacity masks, effects and overlapping transparent art still flatten
  it, and so does a colorize paint the writer can't draw.

The svg crate's tests turn on resvg's raster-images feature to render
the embedded PNGs.

Docs: docs/mcp.md, docs/target-app-parity.md.

docs/mcp.md

@@ -585,6 +585,7 @@ font whose licence (OS/2 `fsType`) forbids subsetting is embedded whole, one tha
 with a warning. Type names its faces by numeric `font-weight` (600 for Semibold and for a Japanese face's W6, 300 for Light, `bold` for 700),
 embedded or not. `svgz` takes the same options and writes the SVG gzipped (`.svgz` files also open,
 place and paste). `run_command document.save {path: "x.svg", svg: {…}}` saves as SVG (or `.svgz`).
+Colorized grayscale and 1-bit images export in their fill color; linked mode writes a coverage PNG, and Tiny 1.2 writes a colorized PNG.
 
 Symbols export as one `<symbol>` with a `<use>` per instance. An instance the def can't stand for is written as its
 own art: one stained by its fill; one scaled while the symbol has strokes (their weight doesn't scale), or rotated or
@@ -4038,6 +4039,7 @@ is accepted); spot colours are Separation colour spaces, and overprinting fills
 `overprints: "discard"`. RGB documents are written in CMYK unless `cmykPostScript: false`. When the file would hold an
 image that can't be decoded, the image is left out, and `warnings` carries "an image couldn't be decoded and is missing
 from the picture" once for all such images.
+Colorized grayscale and 1-bit images use their process or spot ink; the flattener leaves them alone unless they have opacity, a blending mode, an opacity mask or effects, or overlap other transparent art. Binary coverage leaves underlying art untouched. For a grayscale image, Level 3 leaves white (zero-coverage) pixels out, Level 2 writes them white, and gray midtones are written over white at both levels.
 
 PostScript has no transparency: it is flattened first with `flattenerPreset` (`high`, `medium` (default), `low` or a
 saved preset, see `flattener.presets.list`) and `flattener: {…}` options over it (those of

docs/target-app-parity.md

@@ -927,6 +927,7 @@ Moved from the ROADMAP's "Shipped so far" on 2026-10-10. Update it when a featur
   - **CSS swatch libraries:** fractional linear and radial gradient stop positions are preserved, so nearby stops such as 12.5% and 12.890625% remain distinct instead of collapsing to 13%. Reference: [CSS Images 3 color stops](https://www.w3.org/TR/css-images-3/#color-stop-syntax). The original synthetic regression is `palette_io::tests::css_preserves_fractional_gradient_stop_positions` in `crates/color/src/palette_io.rs`. Scores and hours are unchanged.
   - **Swatches:** names follow the colour model and are unique; Swatch Options (process/spot, Global, Gray/RGB/HSB/CMYK/Web, live preview); editing a global or spot swatch recolours every linked fill, stroke and text run in one undo step; multi-select and delete with confirmation; New Swatch and New Color Group dialogs (a group from the selected artwork's colours); swatches in colour groups convert, separate and count like any other. The Swatches panel selects ranges and whole groups, has a find field, and drags swatches to reorder, regroup or paint art; Add Used Colors, Select All Unused, Merge, Ungroup and Sort by Kind; a CMYK document keeps applied colours in CMYK. Swatch libraries: nine generated colour libraries and five gradient libraries in a library panel, saved as `.vcswatches`, `.gpl`, swatch exchange (`.ase`) or CSS, and loaded from `.vcswatches`, `.gpl` and `.ase` files (`.ase` both ways: RGB, CMYK, Lab and Gray; global, spot and process; groups) and from color books (`.acb`, read only: the RGB, CMYK or Lab colors of a book such as a Pantone book a user owns, named with its prefix and suffix, spot unless it says process, #831); `swatch.library.copyToUser` copies a loaded library into the User Defined folder without replacing a file, and a file with the same extension and bytes as a User Defined library opens as that library. Tints of global and spot colours ("Name 40%") stay linked and separate as a percentage of their plate. Spot colours can be defined in Lab (Spot Colors options). A built-in [Registration] swatch prints on every plate.
     Editing, renaming, deleting or merging a global swatch also changes the colors linked to it in graph designs, the art of brushes and the tile that pattern editing's Cancel puts back, in the same undo step as the rest of the art; Default Swatches with replace unlinks them there too.
+  - **Colorized images (#1466):** a fill color applied to a selected grayscale or 1-bit image (`paint.setFill`) colorizes it with black, white, a process color or a spot color, and refuses a process color when the image has an alpha channel ([Convert color modes](https://web.archive.org/web/20251220223850/https://helpx.adobe.com/illustrator/desktop/manage-colors/select-and-adjust-colors/convert-color-modes.html), "Colorize Grayscale or 1-bit images"); black and white are accepted there too. The canvas draws each pixel in the color as far as the pixel is dark, with white pixels transparent; PDF export writes the image in the color (a spot color as its ink, Registration in every ink) with the image as its soft mask; Separations Preview and printed separations show it on its color's plates; native files keep the color. SVG writes the fill color through a coverage mask (or a colorized PNG in Tiny 1.2); EPS writes binary coverage as an image mask in the color's ink, and a grayscale image as ink samples scaled by coverage, with white pixels left out at Level 3 and gray midtones written over white.
     The prompt for deleting several swatches and groups uses the interface language's plural form for the count. Evidence: `deleting_several_swatches_uses_each_count_form` in `crates/ui-egui/src/panels/swatches/tests.rs`.
   - **Colorized images (#1466):** a fill color applied to a selected grayscale or 1-bit image (`paint.setFill`) colorizes it with black, white, a process color or a spot color, and refuses a process color when the image has an alpha channel ([Convert color modes](https://web.archive.org/web/20251220223850/https://helpx.adobe.com/illustrator/desktop/manage-colors/select-and-adjust-colors/convert-color-modes.html), "Colorize Grayscale or 1-bit images"); black and white are accepted there too. The canvas draws each pixel in the color as far as the pixel is dark, with white pixels transparent; PDF export writes the image in the color (a spot color as its ink, Registration in every ink) with the image as its soft mask; Separations Preview and printed separations show it on its color's plates; native files keep the color. EPS and SVG write the image's own pixels.
   - **Missing library files:** a persistent swatch or graphic style library panel whose file is gone at startup reopens and stays in the preferences, showing the file's path with Locate Library… (`ui.libraryPanel.locate`), which reads the file from where it is now into the same panel.