.ai import: paths keep their notes and Show Center

Squashed from #5129 onto main.

docs/target-app-parity.md

@@ -1079,6 +1079,7 @@ Moved from the ROADMAP's "Shipped so far" on 2026-10-10. Update it when a featur
     PDF export and `.ai` saves write a page with a side longer than 14,400 pt with a `UserUnit` (PDF 1.6), its longer side divided by 14,400 and rounded up to the next thousandth, so that no side is longer than 14,400 units (ISO 32000-1, Annex C.2); in PDF 1.3 to 1.5 files and PDF/X files such a page is written in points.
     Placed (linked) files in a `.ai`'s editing data come in as linked images in their place, each showing the low-resolution preview the file keeps of it until its file is found or relinked in the Links panel (a file found next to the document or at its path is read as the document opens). A file with them no longer falls back to its PDF part, so its guides, sublayers and hidden objects open (#1264; `crates/eps/src/import/ai/tests.rs`, `crates/engine/src/tests/links.rs`). In a file opened that way, a gradient with stops in the middle runs its whole ramp across its shape and a gradient object no longer passes its fill to the next path (#1390); text objects with an appearance keep their own text and frame, type of hidden layers stays hidden, and type on later artboards lands on its text objects (#1391); area type whose frame is too short for a line of the fallback font shows its first line, the frame made taller with a warning in the open result (#1392).
     `.ai` and EPS editing-data import keeps template layers, and opens canvas and artboard ruler guides as ruler guides on their layers; guide objects stay editable guide paths (#779; `crates/eps/src/import/ai/tests.rs`, `crates/eps/src/import/tests_native.rs`).
+    `.ai` and EPS editing-data import keeps each path's Attributes panel note (`%AI3_Note:`, `%%Note:`, more lines in `%AI5_NoteMore:`, up to 1,024 characters) and Show Center (`1 Ap`); a note or Show Center applies to every path after it until the next one, and a note before a group or compound path is not theirs (`crates/eps/src/import/ai/tests.rs`, `crates/eps/src/import/tests_illustrator.rs`).
     A `.ai` saved without PDF compatibility (its PDF part only a placeholder page) is placed and pasted from its editing data, as it opens: File › Place places the art of the layers that show on the first artboard (`file.place`'s `page` places another one), and Paste of it as PDF data (`clipboard.importPdf`) takes every object. `document.open` with `pages` naming every page of such a file opens it the same way (`crates/engine/src/cmd/fileio/tests_aiimport.rs`).
   - EPS and DXF in and out, EMF/WMF in and out; PNG (with PNG-8), JPEG, WebP, GIF, TIFF, BMP, Targa and layered PSD export; grayscale TIFFs with an alpha channel or other extra channels place, relink and open, the alpha as the image's transparency (#1466 in part; CCITT Group 3 and planar files with extra channels are not read); PSD and PSB files open and place, linked or embedded, as their merged image in every colour mode and depth (#918). EPS import runs a PostScript Level 3 interpreter written from the PostScript Language Reference: resource categories and `resourceforall`, local and global VM (`currentglobal`/`setglobal`/`gcheck`), `clipsave`/`cliprestore`, subarrays and substrings that share storage, the standard dictionaries in `systemdict`, `dictstack`, `internaldict`, executable filters and strings, `load` by any key, `//name` immediate names, `token`, `execform`, user paths, `cshow`, `rootfont`, `cachestatus`, colour rendering and halftone queries, file `status` and data read with `flushfile`, and `pdfmark` marks dropped (Discord feedback, #466, #469, #474). Masked images (`ImageType 3` in its three interleavings) and reusable streams are read, and an image's several data sources are read in turn, as the reference defines (procedures that read one file get their own rows: such images came in banded, #498). `restore` puts dictionaries back as they were at the `save`, so programs that count their saves in a dictionary read to their end (part of #505). Tiling patterns come in as pattern swatches, uncoloured ones too; Type 3 fonts' glyphs as their outlines, spaced by `ashow`/`widthshow`/`xshow`/`kshow`; mesh and function-based shadings (types 1, 4–7) as gradient meshes; sampled functions (type 0) and Flate/LZW predictors are read. It is tested with programs written from the specification in the ways common generators use these features; Inkscape/cairo EPS files open as vectors. When a file's PostScript still can't be read, it opens as its TIFF preview, its Windows metafile preview (as vectors) or its EPSI preview, and the warning (in the status bar, `document.open`/`app.open`/MCP `open_file` replies and `vectorcraft-cli info`) names the error, the operator that raised it and the procedures it ran in. Legacy PostScript `.ai` files (Illustrator 3–8, written with the prolog that defines their operators) keep their groups and nested groups (`u` … `U`), between and inside clipping groups; EPS and EMF/WMF import nest clips (and groups) at most 128 deep, so a hostile file can't exhaust the stack. DXF TEXT justified Fit or Aligned spans its two points (stretched, or scaled as a whole). PDF export writes type as real, searchable text in embedded subset fonts by default, as Illustrator's PDF presets do (Convert Text to Outlines is an option; printer's marks stay shapes), so text-heavy PDFs stay small (#733). DXF export writes each fill as its outlines followed by its hatch, so laser and cutter software, which skips hatches, gets filled art and type too (#546).
   - The Open and Place dialogs list PostScript `.ps` files and `.epsf` files. A `.ps` file opens and places through the EPS reader (its first page), also when its header is only `%!`, as the `ps` format, which exports don't write (Print to PostScript does); an `.epsf` file opens and places as EPS. Copied in a file manager, these files paste as EPS, and `clipboard.importEps` also reads PostScript whose header is only `%!` (`crates/engine/src/cmd/fileio/tests_epsimport.rs`).