Simplify: add Corner Point Angle Threshold, Convert to Straight Lines and Show Original Path

The Simplify dialog had Tolerance, Preview and the anchor point counts.
It now also has three of the options of the reference app's advanced
Simplify dialog:

- Corner Point Angle Threshold is a slider from 0° to 180° that opens
  at 150°, with its label above it so the dialog stays under the
  420-point width that menu_parameter_dialogs_are_compact allows. An
  anchor whose corner is sharper than the threshold stays a corner, so
  moving the slider right keeps more corners. The dialog sends
  object.path.simplify's cornerAngle as 180° less the threshold, so the
  opening value gives the same result as before.
- Convert to Straight Lines sends straightLines.
- While Preview is on, Show Original Path draws the paths as they were
  before the preview, in a faint band of their layer's color under the
  selection outlines.

The three labels have rows in the 19 catalogs that translate every
label.

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

docs/target-app-parity.md

@@ -537,8 +537,9 @@ Moved from the ROADMAP's "Shipped so far" on 2026-10-10. Update it when a featur
   - Scribble (Effect › Stylize › Scribble…) has a Variation for each of Path Overlap, Curviness and Spacing ([Scribble options](https://helpx.adobe.com/illustrator/using/creating-sketches-mosaics.html)) (`overlapVariation`, `curvinessVariation`, `spacingVariation`), shown in its dialog and in the Appearance panel. A Scribble saved with the earlier single `variation` reads it as the Path Overlap and Spacing variations and draws as before. The angle is stored above -180° and up to 180°, so 270° is stored as -90°.
   - **Simplify feedback and component selection (#1272):** the existing tolerance dialog previews from the original interaction snapshot and shows original/new anchor counts. Preview off and Cancel restore the document and selection; OK is one Undo. A refit or Add Anchor Points clears component indexes only on paths whose geometry changes, keeping their objects selected whole and unchanged paths' components intact. Engine and real-egui frame regressions cover document/selection restoration and grouped paths.
     Public references: [Simplify benefits](https://helpx.adobe.com/illustrator/desktop/draw-shapes-and-paths/modify-paths/simplify-path-benefits.html) and [advanced options](https://helpx.adobe.com/illustrator/desktop/draw-shapes-and-paths/modify-paths/simplify-paths-advanced-options-overview.html).
-    Nearly unchanged appearance is expected when reducing points. Percentage/auto-simplify controls, the corner-angle UI and Show Original are not implemented; the checklist is partial, without raising scores.
+    Nearly unchanged appearance is expected when reducing points. Percentage/auto-simplify controls and Retain my latest settings are not implemented; the checklist is partial, without raising scores.
     Simplify and Add Anchor Points record no undo step when they change no path, and a path they leave as it is keeps its live shape.
+    The Simplify dialog also has Corner Point Angle Threshold, Convert to Straight Lines and Show Original Path. The threshold is a slider from 0° to 180° and opens at 150°: an anchor whose corner is sharper than the threshold stays a corner, so moving the slider right keeps more corners, and the dialog sends `cornerAngle` as 180° less the threshold. While Preview is on, Show Original Path draws the paths as they were before the preview in a wide, faint band of their layer's color under the selection's outlines.
 - **Type:** Character size, leading, baseline shift and horizontal-scale controls account for object/group transforms (#1034): exact document-point sizes, mixed-value display and keyboard increments, range edits, resettable horizontal stretch, undo/redo and native save/reopen (`tests_typescale`, Character panel tests). Point size is the transformed em-height axis, independent of glyph ink bounds; affine rotation, reflection and shear are retained. Group scaling still scales text; preserving font sizes is a separate enhancement. Behaviour reference: [Transform text](https://helpx.adobe.com/illustrator/desktop/design-with-text/edit-format-text/transform-text.html) (public documentation). Text Wrap, Type on a Path effects (Rainbow/Skew/3D Ribbon/Stair Step/Gravity) and Options (Flip, Align to Path, Spacing; OK keeps the type where it is), type on a path's start, centre and end brackets (Selection and Direct Selection drag them to set where the type runs, slide it along its path and, across the path, flip it: #429), Character and Paragraph Styles (override-preserving redefine), paragraph attributes per paragraph (alignment, indents, spacing, hyphenation, hanging punctuation, tab stops, paragraph style, direction, mojikumi and leading model; the Paragraph, Tabs and Paragraph Styles panels act on the paragraphs the Type tool's selection or caret touches, Return continues the paragraph's style, threads and SVG keep them), Area Type Options (rows/columns/inset/first baseline, vertical Align Top/Center/Bottom/Justify per row/column, reflowing non-rectangular frames and text wrap), threaded text across any closed shapes, Fit Headline, the Every-line Composer for justified and ragged text (paragraph-wide breaks for an even rag, Single-line per object from the Paragraph panel menu or `text.setFormat {composer}`). Area type resizes like Illustrator's type areas: a bounding-box handle drag (Selection tool) or Area Type Options Width/Height size the frame and the text reflows at its size (threads too); Direct Selection drags a frame corner or edge (`text.reshapeArea`). Point type still scales. Auto Size: the frame height follows the text after every edit, in the same undo step (rectangular frames of horizontal type in one row; columns get the least height that holds them; a height set by hand or threading turns it off), and the "Auto Size New Area Type" preference gives it to new area type. Shrink Text to Fit (beyond Illustrator): overflowing area type scales its sizes, leading and baseline shifts down by the largest factor (in 0.1 pt steps of the first run, down to a minimum percentage) that fits, at layout time so every export sees it. `text.areaOptions` and `document.inspect` report overflow and the shrink factor. The Selection tool shows the type widget beside selected type's bounding box (hollow on point type, filled on area type); double-clicking it converts between them (Type › Convert To Area Type / Convert To Point Type), keeping the text and its styles in place. Cmd+Shift+C (Align center) works on Windows and Linux too (#1940). Variable fonts list every named instance as a style of their family (Figtree Light to Black and their italics, Bahnschrift, Segoe UI Variable), and the instance chosen is shaped, drawn, outlined and measured at its axis settings; PDF and SVG embed it as that instance. Variation axis sliders are not done. Beyond Illustrator: inline graphics (`text.insertInline`, Type ▸ Insert Inline Symbol) set a document symbol in a run of type as one character that flows, wraps and justifies like a glyph (InDesign-style inline objects, e.g. mana symbols in card rules text): sized to a multiple of the font size, centred on the cap height, opening up tall lines, following Redefine Symbol; a character of its run's size for Character Alignment and Top-to-Top leading, placed by the bidi reordering in right-to-left text (a neutral U+FFFC); drawn on the canvas, kept as live text plus a `<use>` in SVG and as vector art in PDF; Backspace removes it whole. Hebrew and Arabic are laid out right to left with the Unicode bidirectional algorithm (embedded Latin and numbers keep their direction, lines put in visual order after wrapping) in point, area and path type, with caret, selection and arrow keys in visual order; each paragraph's direction comes from its first strong character unless Paragraph Direction sets it (Paragraph panel with Show Indic Options, `text.setFormat {direction}`), and new type aligns to the start of its direction. SVG export outlines right-to-left text. Arabic typefaces: builds made with a craft-fonts checkout that holds its Arabic families (Noto Sans Arabic, the Arabic fallback, plus Cairo, Tajawal, Almarai, IBM Plex Sans Arabic, Noto Kufi Arabic, Amiri, Alexandria, Fustat, Reem Kufi, Aref Ruqaa and Gulzar once craft-fonts adds them, storytold/craft-fonts#11; releases get them when their craft-fonts pin moves) list them in the font menus on desktop; the web build fetches them from beside tLine truncated
 - **Type:** Character size, leading, baseline shift and horizontal-scale controls account for object/group transforms (#1034): exact document-point sizes, mixed-value display and keyboard increments, range edits, resettable horizontal stretch, undo/redo and native save/reopen (`tests_typescale`, Character panel tests). Point size is the transformed em-height axis, independent of glyph ink bounds; affine rotation, reflection and shear are retained. Group scaling still scales text; preserving font sizes is a separate enhancement. Behaviour reference: [Transform text](https://helpx.adobe.com/illustrator/desktop/design-with-text/edit-format-text/transform-text.html) (public documentation). Text Wrap, Type on a Path effects (Rainbow/Skew/3D Ribbon/Stair Step/Gravity) and Options (Flip, Align to Path, Spacing; OK keeps the type where it is), type on a path's start, centre and end brackets (Selection and Direct Selection drag them to set where the type runs, slide it along its path and, across the path, flip it: #429), Character and Paragraph Styles (override-preserving redefine), paragraph attributes per paragraph (alignment, indents, spacing, hyphenation, hanging punctuation, tab stops, paragraph style, direction, mojikumi and leading model; the Paragraph, Tabs and Paragraph Styles panels act on the paragraphs the Type tool's selection or caret touches, Return continues the paragraph's style, threads and SVG keep them), Area Type Options (rows/columns/inset/first baseline, vertical Align Top/Center/Bottom/Justify per row/column, reflowing non-rectangular frames and text wrap), threaded text across any closed shapes, Fit Headline, the Every-line Composer for justified and ragged text (paragraph-wide breaks for an even rag, Single-line per object from the Paragraph panel menu or `text.setFormat {composer}`). Area type resizes like Illustrator's type areas: a bounding-box handle drag (Selection tool) or Area Type Options Width/Height size the frame and the text reflows at its size (threads too); Direct Selection drags a frame corner or edge (`text.reshapeArea`). Point type still scales. Auto Size: the frame height follows the text after every edit, in the same undo step (rectangular frames of horizontal type in one row; columns get the least height that holds them; a height set by hand or threading turns it off), and the "Auto Size New Area Type" preference gives it to new area type. Shrink Text to Fit (beyond Illustrator): overflowing area type scales its sizes, leading and baseline shifts down by the largest factor (in 0.1 pt steps of the first run, down to a minimum percentage) that fits, at layout time so every export sees it. `text.areaOptions` and `document.inspect` report overflow and the shrink factor. The Selection tool shows the type widget beside selected type's bounding box (hollow on point type, filled on area type); double-clicking it converts between them (Type › Convert To Area Type / Convert To Point Type), keeping the text and its styles in place. A double-click on area type's bottom middle handle turns on Auto Size (#1940). Variable fonts list every named instance as a style of their family (Figtree Light to Black and their italics, Bahnschrift, Segoe UI Variable), and the instance chosen is shaped, drawn, outlined and measured at its axis settings; PDF and SVG embed it as that instance. Variation axis sliders are not done. Beyond Illustrator: inline graphics (`text.insertInline`, Type ▸ Insert Inline Symbol) set a document symbol in a run of type as one character that flows, wraps and justifies like a glyph (InDesign-style inline objects, e.g. mana symbols in card rules text): sized to a multiple of the font size, centred on the cap height, opening up tall lines, following Redefine Symbol; a character of its run's size for Character Alignment and Top-to-Top leading, placed by the bidi reordering in right-to-left text (a neutral U+FFFC); drawn on the canvas, kept as live text plus a `<use>` in SVG and as vector art in PDF; Backspace removes it whole. Hebrew and Arabic are laid out right to left with the Unicode bidirectional algorithm (embedded Latin and numbers keep their direction, lines put in visual order after wrapping) in point, area and path type, with caret, selection and arrow keys in visual order; each paragraph's direction comes from its first strong character unless Paragraph Direction sets it (Paragraph panel with Show Indic Options, `text.setFormat {direction}`), and new type aligns to the start of its direction. SVG export outlines right-to-left text. Arabic typefaces: builds made with a craft-fonts checkout that holds its Arabic families (Noto Sans Arabic, the Arabic fallback, plus Cairo, Tajawal, Almarai, IBM Plex Sans Arabic, Noto Kufi Arabic, Amiri, Alexandria, Fustat, Reem Kufi, Aref Ruqaa and Gulzar once craft-fonts adds them, storytold/craft-fonts#11; releases get them when their craft-fonts pin moves) list them in the font menus on desktop; the web build fetches them fLine truncated
 - **Vertical punctuation:** fullwidth `！` (U+FF01) and `？` (U+FF1F) use their nominal glyph upright when no vertical alternate is present, following the Tu fallback in [Unicode UAX #50 §3.1](https://www.unicode.org/reports/tr50/#vo). Code-built test fonts cover point and area type with and without `vert` alternates, retain the rotated fallback for a bracket and long vowel mark, and leave horizontal type unchanged. Tests: `crates/text/src/tests_vertical.rs`.

docs/ui-parity.md

@@ -58,7 +58,7 @@ tools, never checked side by side) isn't captured row by row.
 | Join tool scrubbing, Average, Join | done | Join merges the direct-selected anchors lying on one another along a path, as after Average, into one (#1533) |
 | Average and Join in one step, with a corner or smooth choice for the joined anchor | missing | `path.join` and `path.average` are separate commands, and Join has no corner/smooth choice; [gap 1](gaps.md) |
 | Smooth tool smooths only the stretch of path under the drag | done | #1512 |
-| Simplify (slider, auto, corner angle threshold) | partial | Tolerance, default-on Preview and original/new point counts (#1272); slider, auto-simplify, corner-angle UI and Show Original remain missing |
+| Simplify (slider, auto, corner angle threshold) | partial | Tolerance, default-on Preview and original/new point counts (#1272); Corner Point Angle Threshold, Convert to Straight Lines and Show Original Path; slider, auto-simplify and Retain my latest settings remain missing |
 
 ## Direct Selection, anchors and handles