Keep tests correct and docs current with one test binary per crate

- gpu: the test modules share one GPU_LOCK, and timing and vector_mask
  take it too, so one process drives one wgpu device at a time.
- ui-egui: the wgpu tests in pattern_preview_canvas, adjust_preview_gpu,
  marquee_autoscroll and layout_perf take gpu_lock().
- affinity compound_limits: the child process selects its test by the
  module path (compound_limits::<name>); with --exact, the bare name
  matches no test and the child passes without running the check.
- xtask scorecard reads crates/io/tests/it/corpus.rs.
- Docs and comments name the new test paths and the --test it filters.

docs/target-app-parity.md

@@ -438,10 +438,10 @@ filled bar. This extends UI reachability and does not claim Photoshop-authored s
 |---|---|---|---|
 | Menu wiring | 626/626 menu items dispatch a command (`parity-checklist.md`) | high but shallow | Says nothing about behaviour. |
 | PSD fidelity (rendering) | Corpus oracle 115/170 (68%): 30 differ, 26 have no usable reference, 1 import error. 2026-10-07: io corpus 146/170, psd-tools corpus 236/309 (was 229: Advanced Blending knockouts), Photoshop oracles 132/258 | medium | Push to 170/170 under way (effects/strokes, multi-instance effects, 16/32-bit and colour modes, references for skipped files). |
-| PSD round trip | 169/169 re-import identically; every adjustment layer and blend mode round-trips | high (within corpus) | Floors in `crates/io/tests/corpus.rs`; raise, never lower. Corpora: `cargo xtask corpus --all` (ours: https://github.com/storytold/photocraft-corpus). |
+| PSD round trip | 169/169 re-import identically; every adjustment layer and blend mode round-trips | high (within corpus) | Floors in `crates/io/tests/it/corpus.rs`; raise, never lower. Corpora: `cargo xtask corpus --all` (ours: https://github.com/storytold/photocraft-corpus). |
 | OpenRaster read/write | 2026-10-09: 34 Krita 5.2.9-authored `.ora` files (27 blend modes, groups, pass-through, offsets, opacity, visibility, masks, 16-bit, gray) render within 3/255 of Krita's merged image (30) or differ for known reasons (4: Krita's lighter/darker-colour tie-break, Hard Mix at exactly 1, a linear-light 16-bit document); Krita re-opens our exports and renders them identically to its originals (33/34; Soft Light is written as `svg:soft-light`) | medium (one authoring app) | MyPaint and GIMP files untested. Masks are applied to pixels and layer styles dropped on save (reported). See [OpenRaster](ora.md). |
 | Paint.NET import | 2026-10-09: 14/14 local PDN3 textures preserve editable layers exactly through `.pcraft` and render within 2.142/255 of full-size previews; a supplied 5.x document (1280×720, 11 layers) passes editing/history/native saves and matches its thumbnail within 0.418/255 mean; all 14 blend modes exercised synthetically | medium (limited corpus) | Import only; metadata omitted. More current-version files and full-size exports needed. See [PDN support](pdn.md). |
-| Smart filters / text / effect shapes in PSDs | Measured on our Photoshop-authored set (https://github.com/storytold/photocraft-corpus, `corpus/photoshop`, 258 files): see the per-group floors in `crates/io/tests/corpus.rs` and `crates/engine/tests/photoshop_oracles.rs`. Smart objects and smart filters now survive PSD save and open (41 corpus files, 206 smart objects, round trip strict; Photoshop opens our exports with live filters); re-rendering Photoshop's smart filters with ours matches 5/30 (was 1/30) | low–medium | Remaining re-render gaps are filter maths (Gaussian/Motion Blur, Unsharp Mask, Emboss, Add Noise RNG) and bicubic placement. |
+| Smart filters / text / effect shapes in PSDs | Measured on our Photoshop-authored set (https://github.com/storytold/photocraft-corpus, `corpus/photoshop`, 258 files): see the per-group floors in `crates/io/tests/it/corpus.rs` and `crates/engine/tests/it/photoshop_oracles.rs`. Smart objects and smart filters now survive PSD save and open (41 corpus files, 206 smart objects, round trip strict; Photoshop opens our exports with live filters); re-rendering Photoshop's smart filters with ours matches 5/30 (was 1/30) | low–medium | Remaining re-render gaps are filter maths (Gaussian/Motion Blur, Unsharp Mask, Emboss, Add Noise RNG) and bicubic placement. |
 | Core editing (layers, masks, selections, adjustments, filters, transforms) | Broad engine coverage; many interaction bugs fixed after 0.2.0 (adjustment dialogs, Curves, crop, Move/Transform modifiers, gesture origin) | medium | Fixes not yet user-validated. |
 | UI / UX polish | Shortcut audit 214 → 0 failures; dock, Layers rows and menus reworked; first visual-QA sweep found 14 defects (#147–#157). 2026-10-07: the keyboard-only shortcuts with no menu item (⌥[ ⌥] ⌥, ⌥. layer navigation, ⇧⌥[ ⇧⌥] to extend the selection, 1–0 for opacity and ⇧ for flow or fill, ⇧[ ⇧] hardness, ⌥⌘T to transform a copy and ⌥⇧⌘T to step and repeat), ⌥-click colour sampling with painting tools, double-click a Layers row for Layer Style, File › New from Clipboard, a centred main window and remembered Liquify settings (#352, #417, #350, #368, #419, #418). 2026-10-09: canvas zoom is physical at any display scale — 100% is one document pixel per physical display pixel, and every screen-space overlay, cursor, scrollbar, navigator and fit follows it (#1943) | low–medium | Needs recurring visual QA with realistic documents. |
 | Tools | 2026-10-10: Pencil, Mixer Brush, Color Replacement, Patch, Content-Aware Move, Vertical Type, Pattern Stamp and Rotate View are toolbar tools. The only tool still missing is Art History Brush: Frame landed (#2914), Red Eye is a live toolbar tool (`paint.redEye`, TOOL-213-17) and Perspective Crop landed (2026-10-10, #1043, `image.perspectiveCrop`) | low–medium | Patch has a live healing preview. Content-Aware Move is done (`TOOL-213-4`): Move/Extend, Structure/Color, Sample All Layers, Transform On Drop, and a live result preview for every selection the command takes (coarse first for large ones, then exact; 2026-10-16, #6680). Magic/Background Eraser added; live gradients in progress (#180). Magnetic Lasso added 2026-10-08 (live-wire edge tracing, Width/Contrast/Frequency, `select.magneticLasso`). Pattern Stamp added 2026-10-08 (S flyout, `paint.patternStamp`, Aligned / Impressionist). Rotate View (2026-10-09) turns the canvas camera around its centre without rewriting pixels; Reset View and Match Rotation copy the angle. Crop rotation (2026-10-09, #1792): dragging outside the crop frame turns it (⇧ 15° steps, angle readout), and ↵ rotates the document and crops in one undo step (`image.crop` `angle`); the frame turns over the image as in Photoshop's Classic Mode, and the options-bar Straighten is still missing. |