EPS: a freeform gradient's image drawn more than once writes its samples once

A freeform gradient's image was sampled, encoded and written inline at
every fill, outside the reuse placed images have. Fields now go through
the same codes and placements: a fill whose encoded image (color setup,
image dictionary, filter, operator and samples) matches one already
kept draws from it, so its samples are written once in the setup as
VCim<i>. A field drawn once is still written where it is drawn.

A fill whose placement can't be drawn, or that arrives when the page is
already at the 256 MB limit, is no longer sampled first, and a field
image taken back with art that passed the limit is forgotten.

docs/target-app-parity.md

@@ -622,6 +622,7 @@ since 2026-10-01.
 - **Warp effects bend images:** a Warp effect on an image, or on a group that holds one, bends the image's pixels with its frame, as the Warp effect is documented to distort bitmap images in [Reshaping with effects](https://helpx.adobe.com/illustrator/using/reshaping-objects-effects.html): after the last effect, the image is cut into 10 × 10 cells of two triangles, each a clipped piece under its own affine map. Effects after the Warp reshape only the frame, a second Warp bends the same pieces, and warps saved without a version bend the pixels with their earlier map, as they bend the frame. A placed gradient on a group that holds the image follows the group's bounds as the pieces draw them. SVG writes the image once for the pieces; PDF, EPS, `.ai` and PNG write the bent pieces. The images stay unbent when their pieces would make the art pass 2 million objects, and so does an image whose frame keeps its shape past the anchor budget. A grayscale image's fill color now colorizes the pieces of a warp or an envelope, and an image under any geometry effect keeps that color and its smoothing setting. Existing documents with a Warp effect on an image, or on a group that holds one, draw differently: before, the image showed unbent, cut by the bent frame. So do existing documents with a colorized image under an envelope or a geometry effect, or an image drawn without smoothing under a geometry effect: before, those lost the color or the setting. The cell count and the limits are VectorCraft's own (effects `tests::warped_images_stay_within_the_object_budget`, `tests::warped_images_keep_document_keys_and_hidden_images_apart`, `tests::an_image_whose_frame_passes_the_budget_stays_whole`, `tests::effects_after_a_warp_reshape_an_images_frame_and_not_its_pieces`, `tests::an_images_pixels_take_the_map_their_warps_version_names`, `tests::an_image_under_a_geometry_effect_keeps_its_color_and_smoothing`, `tests::a_nested_groups_gradient_follows_its_warped_image`; engine `warp_images::an_images_pixels_bend_with_effect_warp`, `a_warped_image_keeps_its_bend_in_svg`, `a_warped_image_keeps_its_bend_in_pdf`, `a_warped_image_keeps_its_bend_in_ai`, `a_warped_image_keeps_its_bend_in_eps`, `a_warped_image_keeps_its_bend_in_png`, `svg_writes_an_image_clipped_twice_in_a_users_group_twice`, `expand_appearance_of_a_warped_image_draws_as_the_canvas_did`, `a_colorized_image_keeps_its_color_when_warped`, `a_warp_on_a_group_bends_the_image_in_it`, `envelope_distort::a_colorized_image_keeps_its_color_in_an_envelope`). Scores and hours unchanged.
 - **`.ai` files keep an image's Warp live:** an embedded image whose appearance is one Warp effect, with no opacity mask, is saved to the `.ai` editing data with an art style of that Warp: its bent pieces are its drawn look, and the image itself follows on `%_` lines, as for other styled objects. Opening an `.ai` file reads such an image as the image with its Warp live, its pixels, placement, name and opacity kept, when the live warp draws as the file's drawn look and the import has a comparison left; otherwise the drawn look stays, with the drawn-look note. The Warp effect applies to bitmap images ([the help page](https://helpx.adobe.com/illustrator/desktop/manage-objects/reshape-transform-objects/distort-and-transform-effects-in-illustrator.html)), and native files keep live effects ([the help page](https://helpx.adobe.com/illustrator/desktop/get-started/learn-the-basics/supported-file-formats-in-illustrator.html)). A linked image with a Warp is saved as its drawn art, as before, and its live Warp is not saved. Images with an opacity mask, and images with a Warp and another effect or with another geometry effect, are saved and opened as their drawn art. Existing `.ai` files with an embedded image on `%_` lines open differently: before, that image also came in beside its drawn look. Which images keep the Warp and the comparison are VectorCraft's own rules (eps `ai_editing::tests::an_image_with_a_warp_reads_back_with_its_warp_live`, `an_image_whose_warp_draws_otherwise_than_its_look_keeps_its_look`, `an_image_on_hidden_lines_does_not_come_in_beside_its_look`, `other_warped_images_are_written_as_their_drawn_art`, `import::ai::read::ops::tests::an_image_takes_a_style_of_one_warp_alone`). Scores and hours unchanged.
 - **EPS writes a repeated image's samples once:** an image drawn more than once in an EPS file (the pieces of an envelope or a Warp effect, copies of one image, or one image in a symbol's instances) has its compressed samples written once in the setup, and each placement reads them from there: a reusable stream rewound for each placement at Language Level 3 ([PostScript Language Reference, 3rd ed., §3.13](https://www.adobe.com/jp/print/postscript/pdfs/PLRM.pdf)), and an array of strings of at most 49,152 bytes fed to the image by a procedure at Level 2. An image drawn once is written where it is drawn, as before. The 256 MB limit on the page counts the samples once, so an envelope of a large photo no longer loses pieces to it. A colorized image is reused per ink (eps `tests::an_image_placed_twice_writes_its_samples_once_at_both_levels`, `tests::an_envelopes_image_pieces_draw_one_copy_of_its_samples`, `tests::each_ink_of_a_colorized_image_placed_twice_is_written_once`, `tests::samples_longer_than_a_string_are_reused_at_both_levels`, `tests::the_page_limit_counts_a_repeated_images_samples_once`). Scores and hours unchanged.
+- **EPS writes a repeated freeform gradient's image once:** a freeform gradient whose image samples the same on more than one fill (copies of a shape moved with their points, or one shape in a symbol's instances) has its samples written once in the setup, as a repeated image's are, and a fill whose image differs (other colors, another size) gets its own. A freeform fill drawn once is written where it is drawn, as before, and a fill whose placement cannot be drawn, or that arrives when the page is already at the 256 MB limit, is no longer sampled first (eps `tests::a_freeform_gradients_image_drawn_twice_writes_its_samples_once`, `tests::freeform_gradients_sampled_differently_dont_share_an_image`, `tests::a_field_taken_back_at_the_page_limit_leaves_no_image_behind`). Scores and hours unchanged.
 - **PDF writes a warped image once:** with downsampling on, the pieces of an image bent by a Warp effect are resampled for the widest and the highest size any piece places the image at, so every piece paints one image XObject (a colorized image: one colorized image and its soft mask), instead of one image for each size a piece is placed at. Another placement of the same image is still resampled for its own size. Without downsampling, a colorized image and a CMYK image with a grayscale image mask on its grid are decoded and encoded once for all the sizes they are placed at (pdf `tests::compression::a_warped_image_is_written_once_for_all_its_pieces`, `tests::colorize::a_colorized_warped_image_is_written_once_for_all_its_pieces`, `export::images::tests::colorized_and_grid_masked_images_are_made_once_for_every_size_without_downsampling`). Scores and hours unchanged.
 - **Distort Appearance with Transform effect options:** with Envelope Options › Distort Appearance on, a path whose Transform effect has Scale Strokes & Effects or Transform Patterns on, or copies it with a gradient, is bent as the same per-copy art it draws and expands as outside the envelope: each copy's own stroke weight, dashes, pattern placement and gradient (effects `bake::tests`). Scores and hours unchanged.
 - **Fitted gradients turn with the Transform effect:** a gradient fitted to the object (not placed with the Gradient tool) turns, reflects and stretches with the object when its Transform effect rotates, reflects or scales it unevenly, as Object › Transform already does: the gradient is fixed to its fit on the geometry the effect takes, then follows the effect and the effects after it as a placed gradient does. Under moves and even scales it draws as a refit does, and a Transform effect that scales the object to nothing across leaves it fitted, with Scale Strokes & Effects or Transform Patterns on too, and on each copy. This holds on the canvas and in Object › Expand of the fill, for an object's own effects, a fill's or stroke's own, and a group's, where the gradients fitted to its paths, to its own fill, to the groups inside it and to its images' and symbol instances' own fills each fix to their own object's fit. Existing documents with such a Transform effect on fitted-gradient art draw differently: before, the gradient refit to the turned outline. The Gradient tool still shows a fitted gradient's vector at its unturned fit. How gradients follow the effect is VectorCraft's own rule; what the effect does to the object is described in [Distort and transform effects](https://helpx.adobe.com/illustrator/desktop/manage-objects/reshape-transform-objects/distort-and-transform-effects-in-illustrator.html) (effects `bake::tests::a_fitted_gradient_turns_reflects_and_stretches_with_a_transform_effect`, `bake::tests::a_transform_effect_that_scales_to_nothing_leaves_a_fitted_gradient_fitted`, `group::tests::a_groups_transform_turns_the_gradients_fitted_to_its_members_and_its_own_fill`; render `objectfx::a_fitted_gradient_turns_and_reflects_with_its_transform_on_the_canvas`; engine `objexpand::a_fitted_gradient_turned_by_a_transform_expands_as_the_canvas_draws_it`). Scores and hours unchanged.