Library panels: a persistent panel whose file is gone stays listed as missing

At startup, a persistent swatch or graphic style library panel whose
file could not be read was closed and left out of the preferences,
with only a status-bar note. The next preferences save dropped it, so
moving or renaming the file once lost the panel and its settings.

Such a panel now reopens where the saved layout had it and stays in
the preferences. Its tab shows the file's name without the extension,
and its body shows "Missing:" with the file's path and a Locate
Library… button. The new command ui.libraryPanel.locate {panel,
path?} loads the library from the file given, or from one picked in
an open dialog, and shows it in the same panel, which keeps its view,
Show Find Field and Persistent. When the file's library is open in
another panel, the missing panel closes and that panel is brought
forward and made persistent.

A persistent panel whose User Defined library file is deleted while
the app runs shows the library as missing the same way; other panels
still close. window.swatchLibrary and window.graphicStyleLibrary take
a missing library's id, so a closed missing panel opens again.
Previous Library and Next Library are dimmed in a missing panel's
menu.

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

docs/mcp.md

@@ -1574,11 +1574,21 @@ of its kind in that panel (what Previous Library and Next Library do; a library
 brought forward instead), `view` is `smallThumb`, `mediumThumb`, `largeThumb`, `smallList` or `largeList`,
 `showFind` shows or hides the find field, and `persistent: true` is the panel menu's Persistent: the panel
 reopens when the app starts, with its view and find field, where the saved layout had it (or floating). A
-library loaded from a file is read again from its path; one whose file is gone is left out, and the status bar
-says which. A closed persistent panel can still be set, so `persistent: false` stops it reopening. The reply
-is `{panel, kind, library, view, showFind, persistent, open}`, and `ui.inspect` lists every panel's settings
+library loaded from a file is read again from its path. When the file is gone, the panel still reopens and
+stays in the preferences: its tab shows the file's name, its body shows `Missing:` with the file's path and a
+Locate Library… button, and the status bar names the file. A persistent panel whose User Defined library's
+file is deleted while the app runs stays open with the same tab and `Missing:` body; any other panel closes.
+A closed persistent panel can still be set, so `persistent: false` stops it reopening. The reply is
+`{panel, kind, library, view, showFind, persistent, open}`, and `ui.inspect` lists every panel's settings
 under `ui.library_panels`.
 
+`ui.libraryPanel.locate {panel, path?}` is Locate Library…: it loads the library at `path` (without one, it
+asks for a file) as Other Library… does and shows it in the open panel `panel`, which keeps its view, find
+field and Persistent, and answers as `ui.libraryPanel` does. When the file's library already has a panel open,
+`panel` closes and is forgotten, and that panel is brought forward, made persistent when `panel` was.
+`window.swatchLibrary` and `window.graphicStyleLibrary` also take a missing library's id, so a closed missing
+panel opens again; they answer its file's name without the extension and `count: 0`.
+
 ```json
 {"name":"invoke_menu","arguments":{"command":"window.swatchLibrary","params":{"library":"pastels"}}}
 {"name":"invoke_menu","arguments":{"command":"ui.libraryPanel","params":{"panel":"library:swatches:pastels","view":"smallList","persistent":true}}}

docs/target-app-parity.md

@@ -700,6 +700,7 @@ Moved from the ROADMAP's "Shipped so far" on 2026-10-10. Update it when a featur
 - **Paint and appearance (M3):**
   - **CSS swatch libraries:** fractional linear and radial gradient stop positions are preserved, so nearby stops such as 12.5% and 12.890625% remain distinct instead of collapsing to 13%. Reference: [CSS Images 3 color stops](https://www.w3.org/TR/css-images-3/#color-stop-syntax). The original synthetic regression is `palette_io::tests::css_preserves_fractional_gradient_stop_positions` in `crates/color/src/palette_io.rs`. Scores and hours are unchanged.
   - **Swatches:** names follow the colour model and are unique; Swatch Options (process/spot, Global, Gray/RGB/HSB/CMYK/Web, live preview); editing a global or spot swatch recolours every linked fill, stroke and text run in one undo step; multi-select and delete with confirmation; New Swatch and New Color Group dialogs (a group from the selected artwork's colours); swatches in colour groups convert, separate and count like any other. The Swatches panel selects ranges and whole groups, has a find field, and drags swatches to reorder, regroup or paint art; Add Used Colors, Select All Unused, Merge, Ungroup and Sort by Kind; a CMYK document keeps applied colours in CMYK. Swatch libraries: nine generated colour libraries and five gradient libraries in a library panel, saved as `.vcswatches`, `.gpl`, swatch exchange (`.ase`) or CSS, and loaded from `.vcswatches`, `.gpl` and `.ase` files (`.ase` both ways: RGB, CMYK, Lab and Gray; global, spot and process; groups) and from color books (`.acb`, read only: the RGB, CMYK or Lab colors of a book such as a Pantone book a user owns, named with its prefix and suffix, spot unless it says process, #831); `swatch.library.copyToUser` copies a loaded library into the User Defined folder without replacing a file, and a file with the same extension and bytes as a User Defined library opens as that library. Tints of global and spot colours ("Name 40%") stay linked and separate as a percentage of their plate. Spot colours can be defined in Lab (Spot Colors options). A built-in [Registration] swatch prints on every plate.
+  - **Missing library files:** a persistent swatch or graphic style library panel whose file is gone at startup reopens and stays in the preferences, showing the file's path with Locate Library… (`ui.libraryPanel.locate`), which reads the file from where it is now into the same panel.
   - **Colour:** a Color Picker (colour field, H/S/B/R/G/B channel slider, HSB/RGB/Lab/CMYK fields, hex, web-only snapping, out-of-gamut correction); the Color panel shows a selected colour in its own model and, with nothing selected, the new-art defaults in the mode picked last, which it keeps between sessions; Alt-click paints the other proxy; proxies look through groups and show "?" for mixed paint; Invert, Complement, Apply Last Color (`,`) and Apply Last Gradient (`.`) keep the colour model; every paint command feeds the recent colours. The Color Guide has 21 harmony rules, Steps and Variation options and Limit to Library. Adjust Color Balance (its Global mode shifts tints) and Saturate preview live; Edit Colors and Recolor also reach meshes, images and patterns. Recolor Artwork has colour reduction, five recolour methods, presets, Limit to Library, a colour-wheel Edit tab and Edit Color Group; a local Color Themes panel saves five-colour themes. Fill/Stroke chips open swatch and mixer popovers (the Properties panel has the Control bar's Fill and Stroke chips, Stroke link and weight spinner, with nothing selected too), panels have Illustrator's Window menu keys (Align Shift+F7, Transform Shift+F8, Pathfinder Cmd+Shift+F9, Layers F7, Character Cmd+T…; every panel can be given one in Edit › Keyboard Shortcuts), and Eyedropper Options pick up and apply chosen attributes (Alt and Shift+Alt, image pixels). An ICC CMYK profile converts straight into the RGB working space (not through sRGB, so a wider space such as Wide Gamut RGB keeps colours sRGB can't hold) with the colour settings' black-point compensation, on the canvas and in RGB exports alike (the built-in Generic CMYK compensates both ways, so RGB black separated to a rich black displays as black again). Fills and strokes can overprint (Attributes panel, Overprint Black options), and CMYK documents blend in inks on screen, in PDF and when flattening. Document Color Mode converts the art, symbols, pattern tiles and swatches through the colour settings: Gray stays Gray, RGB greys separate into four-colour greys and a rich black as Illustrator does, or go on the black plate only with `grays: "black"` (also for `document.open {colorMode}`).
     View › Proof Setup › Color blindness – Tritanopia-type turns Proof Colors on and proofs the canvas with the tritanopia simulation of Brettel, Viénot and Mollon (1997). The Separations Preview panel's Proof Setup list offers the same target (`view.proofSetup {target: "tritanopia"}`). Grays keep their value.
   - **Color Picker layout (#2008):** a centered draggable header, equal-width actions above aligned HSB/RGB/Hex and Lab/CMYK fields, compact field and slider, and warnings below the preview. No horizontal scrolling; narrow windows stack the sections with vertical scrolling. Tests in `dialogs/color_picker.rs` cover actual pointer/key input, typed values before OK/Enter, Cancel/Escape rollback, one Undo step, mode-size stability, warnings and layout at two UI scales. The screen sampler sits above the field and the upstream two-grid Tab order is retained. AccessKit regressions check the action names and each channel slider's displayed value, units and range. German and enlarged English UI renders were reviewed locally; no reference images are shipped. This is a layout improvement, with no change to scores or remaining-hour estimates.

docs/ui-parity.md

@@ -243,7 +243,7 @@ empty), without opening the dialog.
 | SVG Interactivity, Retype, Comments, Version History panels | missing | the last two are cloud features (out of scope) |
 | Workspaces (save, reset, switch) | done | |
 | Background Export: a progress dialog with the file name, the artboard count and a bar (busy for one artboard and for formats made in one go), Cancel (Esc) and Continue in Background; it opens after 0.4 s and never over another dialog. A cancelled export writes no file | done | #2564; on the shared `vectorcraft_doc::cancel` token (#2546), so a cancelled render keeps no half-drawn pattern tile or effect raster. The bar moves between artboards, not within one. Save As, Export for Screens and Export Selection don't show it yet |
-| Swatch and graphic style library panels: each library opens in a panel of its own, several at once, that floats, groups, docks and closes like any panel; opening an open library brings its panel forward; Previous / Next Library change the library in place; the panel menu's Persistent reopens the panel at startup with its view and find field (a library loaded from a file is read again, a missing file is skipped with a status-bar note) | done | #2603; panel ids `library:<kind>:<id>`, `ui.libraryPanel {panel, library?, view?, showFind?, persistent?}`; the library panels have no sort option, as before |
+| Swatch and graphic style library panels: each library opens in a panel of its own, several at once, that floats, groups, docks and closes like any panel; opening an open library brings its panel forward; Previous / Next Library change the library in place; the panel menu's Persistent reopens the panel at startup with its view and find field (a library loaded from a file is read again; when its file is missing the panel reopens showing the file's path with Locate Library…, and the status bar names the file) | done | #2603; panel ids `library:<kind>:<id>`, `ui.libraryPanel {panel, library?, view?, showFind?, persistent?}`, `ui.libraryPanel.locate {panel, path?}`; the library panels have no sort option, as before |
 | DXF export/import preserves intended curve closure | done | #1299; R13–2018 closed SPLINE bit set/read; an open curve ending at its start stays open; knots and control points unchanged; native CIRCLE/ARC export and CNC preset remain pending |
 | macOS save sheet: choose the format from a menu | done | #866; the save panel is VectorCraft's own `NSSavePanel` with its Format menu set before the sheet opens (`apps/vectorcraft/src/mac_save_format.rs`); #1855 had withdrawn the menu that was added after the sheet began, which made Save As, Save a Copy and the first Save show no sheet |
 | Preferences: every option acts | partial | ~16 stored but unused (#394) |