Brushes: New Brush and Bristle Brush Options take a bristle brush name of at most 31 characters

Squashed from #3312 onto main.

docs/mcp.md

@@ -1236,7 +1236,7 @@ already walks Image Trace. Short agent entry points:
   pattern tiles and graphic styles count, and so do the strokes in the art of a brush that is used. The art of a brush
   that is not used does not count, so a brush whose own art is the only art that paints with it is listed.
 - Brushes: `brush.list`, `brush.get {name}`, `brush.apply {name, ids?}`, `brush.new {type, name?, params?, ids?}`,
-  `brush.setCurrent {name}`, `brush.options {name, params?}`, `brush.delete {name} | {names}`,
+  `brush.setCurrent {name}`, `brush.options {name, params?, newName?}`, `brush.delete {name} | {names}`,
   `brush.duplicate {name, newName?} | {names}`, `brush.freehand`, `object.expandBrush {ids?}`. `brush.new`,
   `brush.duplicate` and `brush.options` trim the white space around the name they are given. A blank `name` gives
   the type's default name ("New Calligraphic Brush" for a calligraphic brush), and a blank `newName` gives
@@ -1244,7 +1244,11 @@ already walks Image Trace. Short agent entry points:
   `brush.new` or `brush.options` without a `key` takes the color that the art's fills and strokes use most (on a tie,
   the one found first), or black when they use no solid color. `brush.options` changes only the fields of
   `colorization` and of an art brush's `scale` that `params` gives, so `{colorization: {method: "hueShift"}}` keeps a
-  Hue Shift brush's key.
+  Hue Shift brush's key. `brush.new` and `brush.options` take a bristle brush name of at most 31 characters:
+  `brush.new` refuses a longer one, counting the number it adds to a taken name, and `brush.options` refuses a
+  longer `newName`. `brush.duplicate` does not check the length. A bristle brush that already has a longer name
+  keeps it, and `brush.options` without a new name, or with a `newName` that only trims the white space around the
+  name, does not refuse. Other brush types take a name of any length.
 - Variables: `variable.list`, `variable.define {name, kind: text|visibility|image|graph}`, `variable.bind {variable, ids?}`,
   `variable.makeTextDynamic`, `variable.makeVisibilityDynamic`, `variable.makeImageDynamic`, `variable.makeGraphDynamic`,
   `variable.unbind`, `variable.rename`, `variable.delete`, `variable.highlight` (image values are file paths, graph

docs/target-app-parity.md

@@ -727,6 +727,7 @@ Moved from the ROADMAP's "Shipped so far" on 2026-10-10. Update it when a featur
     Art Brush Options' Width (1% to 1000%) and Pattern Brush Options' Scale (1% to 10000%) each have a slider beside the field, over the same range in whole percents; screen readers name the slider as its row and read the field's value.
     Scatter, Art and Pattern Brush Options have the Tips button for Colorization that the [Brushes](https://web.archive.org/web/20241230205225/https://helpx.adobe.com/illustrator/using/brushes.html) page (archived copy) describes, beside Method. It opens Colorization Tips, which shows each method's name and what it does beside a sample of the brush, as OK would make it, painted with that method on a blue stroke; Hue Shift's sample uses the dialog's Key Color. `ui.dialog.set {field: "tips", value: true}` opens it. Screen readers name the button, the popover and each sample.
     Hue Shift set by `brush.new` or `brush.options` without a key color takes the color the art's fills and strokes use most, as Brush Options already offers it, following the Brushes page: "By default, the key color is the most prominent color in the art" (<https://web.archive.org/web/20241230205225/https://helpx.adobe.com/illustrator/using/brushes.html>). The page does not state how prominence is measured. Counting the fills and strokes that use each solid color, with the first one found winning a tie and black for art with no solid color, is VectorCraft's own rule. A `brush.options` edit that gives only the method keeps the brush's key color, and one that gives only an art brush's start guide keeps its end guide. Evidence: `tests_brushsym::hue_shift_without_a_key_takes_the_most_used_art_color`, `tests_brushsym::art_brush_options_keep_the_scale_fields_an_edit_leaves_out`.
+    Bristle Brush Options and `brush.new` take a bristle brush name of at most 31 characters, as the Brushes page states for the Bristle Brush Options. The Name field stops taking characters at 31, and `brush.new` and `brush.options` refuse a longer new name with an error that names the limit. The page does not say how the limit counts characters or what happens to longer names already saved; counting characters and the number added to a taken name, keeping longer saved names, and leaving `brush.duplicate` unlimited are VectorCraft's own rules. A bristle brush that a document or a saved file already holds under a longer name keeps it, and the other brush types take a name of any length. Test: `bristle_brush_names_have_at_most_31_characters` in `tests_brushsym.rs`. Public reference: [Brushes](https://web.archive.org/web/20241230205225/https://helpx.adobe.com/illustrator/using/brushes.html) (archived copy).
     In the Brushes panel, Shift-click selects a range of brushes and Ctrl/Cmd-click adds or removes one. Delete Brush and Duplicate Brush then act on all of them (`brush.delete {names}`, `brush.duplicate {names}`).
     Document Info has a Brushes category after Graphic Styles. It lists the Brushes panel's brushes, or with Selection Only it lists the brushes that the selected objects' strokes use. The Document Info report and Package's report list them too (`document.info {category: "brushes"}`, `brushNames`).
     The Brushes panel menu's Select All Unused selects the brushes that are not used in the document, as the [Brushes](https://web.archive.org/web/20241230205225/https://helpx.adobe.com/illustrator/using/brushes.html) page (archived copy) describes. A brush counts as used when a stroke paints with it in the art (opacity masks included), in symbols, graph designs, pattern tiles or graphic styles, or in the art of a used brush (`brush.unused`).