Liquify: no Twirl Counterclockwise tool, Alt with Twirl Clockwise does it

The reference application's Liquify has Twirl Clockwise only; holding
Alt (Option on macOS) while using it twirls counterclockwise. PhotoCraft
had an extra Twirl Counterclockwise tool on the strip, and #9598 had just
given it a mirrored icon.

Twirl Counterclockwise leaves the tool strip (LiquifyTool::ALL, 11 to
10 tools) and the rotate-ccw icon #9598 added goes with it (asset,
icon_data entry, ATTRIBUTION count back to 113). Alt already reversed
Twirl Clockwise at stroke-down; that stays. The TwirlCcw variant stays as
a stroke's direction: Alt-strokes record `twirlCcw`, and filter.liquify
strokes and older saved strokes naming it still replay as Twirl
Clockwise reversed (the command doc says so). Selecting it as the tool
(control channel `tool: "twirlCcw"`, or a preference saved by an older
version) is refused with an error that says to choose twirlCw and hold
Alt; the rest of the settings still apply and the dialog opens.

Tests: the_tool_strip_has_no_twirl_counterclockwise (no such tool, label
or missing icon on the strip, C is Twirl Clockwise, `twirlCcw` as the
tool is an Err and leaves the tool, an old saved preference naming it
opens); alt_with_twirl_clockwise_twirls_counterclockwise (the field
displacement a dab leaves right of the centre points up without Alt and
down, mirrored, with Alt). twirl_counterclockwise_has_its_own_mirrored_icon
and the twirlCcw row of alt_reverses_twirl_and_swaps_pucker_and_bloat
are removed. The i18n labels for Twirl Counterclockwise stay (the
variant's label).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

ATTRIBUTION.md

@@ -34,7 +34,7 @@ next to them.
 | `epaint_default_fonts::EGUI_ICONS` (build input; deflated into `OUT_DIR/egui_fonts/egui-icons.ttf.deflate`, registered by `crates/ui-egui/src/egui_fonts.rs`) | egui-icons, five-glyph subset of emoji-icon-font | John Slegers | [egui fork at 6d518fc](https://github.com/storytold/egui/tree/6d518fc799681571963842f95b55a6b68431b15a/crates/epaint_default_fonts/fonts), [original](https://github.com/jslegers/emoji-icon-font); egui subset, unmodified here | MIT; Copyright (c) 2014 John Slegers; full upstream notice in [NOTICE](NOTICE) |
 | `assets/fonts/Inter-Regular.ttf`, `Inter-Medium.ttf`, `Inter-SemiBold.ttf` | Inter 4.001 (UI font) | The Inter Project Authors (Rasmus Andersson) | <https://github.com/rsms/inter> | SIL OFL 1.1, [`assets/fonts/OFL-Inter.txt`](assets/fonts/OFL-Inter.txt) |
 | `assets/fonts/JetBrainsMono-Regular.ttf` | JetBrains Mono 2.305 (numeric font) | The JetBrains Mono Project Authors | <https://github.com/JetBrains/JetBrainsMono> | SIL OFL 1.1, [`assets/fonts/OFL-JetBrainsMono.txt`](assets/fonts/OFL-JetBrainsMono.txt) |
-| `assets/icons/*.svg` except `slice-knife.svg`, `slice-select.svg`, `font-similar.svg`, `font-variable.svg`, `sampler.svg`, `artboard.svg`, `perspective-crop.svg`, `frame-placeholder.svg`, `ellipse-dashed.svg`, `gradient.svg`, `type-mask.svg`, `type-mask-vertical.svg`, `text-warp.svg`, `clip-below.svg`, `clip-release.svg`, `layer-mask.svg`, `adjustment-layer.svg`, `brush-replace.svg`, `quick-selection.svg`, `eraser-background.svg`, `eraser-magic.svg`, `lasso-magnetic.svg`, `direct-select.svg`, `convert-point.svg`, `pen-add-anchor.svg`, `pen-delete-anchor.svg`, `pen-freeform.svg`, `pen-curvature.svg`, `bandage-sparkle.svg`, `painting-symmetry.svg`, `symmetry-*.svg`, `path-op-*.svg` and `marquee-{row,column}.svg`, `align-edge-*.svg` and `distribute-*.svg` (114 files; `star-filled.svg` is `star.svg` with a solid fill, `rotate-ccw.svg` is `rotate-cw.svg` mirrored) | Lucide icons | Lucide Icons and Contributors | <https://github.com/lucide-icons/lucide> (`icons/<name>.svg`; `align-*` are now named `text-align-*` upstream) | ISC, [`assets/icons/LICENSE-lucide.txt`](assets/icons/LICENSE-lucide.txt) |
+| `assets/icons/*.svg` except `slice-knife.svg`, `slice-select.svg`, `font-similar.svg`, `font-variable.svg`, `sampler.svg`, `artboard.svg`, `perspective-crop.svg`, `frame-placeholder.svg`, `ellipse-dashed.svg`, `gradient.svg`, `type-mask.svg`, `type-mask-vertical.svg`, `text-warp.svg`, `clip-below.svg`, `clip-release.svg`, `layer-mask.svg`, `adjustment-layer.svg`, `brush-replace.svg`, `quick-selection.svg`, `eraser-background.svg`, `eraser-magic.svg`, `lasso-magnetic.svg`, `direct-select.svg`, `convert-point.svg`, `pen-add-anchor.svg`, `pen-delete-anchor.svg`, `pen-freeform.svg`, `pen-curvature.svg`, `bandage-sparkle.svg`, `painting-symmetry.svg`, `symmetry-*.svg`, `path-op-*.svg` and `marquee-{row,column}.svg`, `align-edge-*.svg` and `distribute-*.svg` (113 files; `star-filled.svg` is `star.svg` with a solid fill) | Lucide icons | Lucide Icons and Contributors | <https://github.com/lucide-icons/lucide> (`icons/<name>.svg`; `align-*` are now named `text-align-*` upstream) | ISC, [`assets/icons/LICENSE-lucide.txt`](assets/icons/LICENSE-lucide.txt) |
 | `assets/icons/{check,chevron-down,chevron-left,chevron-right,chevron-up,chevrons-left,chevrons-right,circle,clock,compass,info,link,link-2,lock,minus,monitor,moon,move,navigation,plus,search,square,trash,triangle,type,x,zoom-in}.svg` | Lucide icons derived from Feather (subset of the row above) | Cole Bemis (Feather), Lucide Contributors | <https://github.com/feathericons/feather> via Lucide | MIT (Feather) and ISC (Lucide), [`assets/icons/LICENSE-lucide.txt`](assets/icons/LICENSE-lucide.txt) |
 | `assets/icons/slice-knife.svg` | Slice tool glyph | PhotoCraft contributors | Original work | MIT OR Apache-2.0 |
 | `assets/icons/slice-select.svg` | Slice Select tool glyph | PhotoCraft contributors | Original work | MIT OR Apache-2.0 |