Export: warnings name an option the chosen format doesn't read

`document.export`, `document.serialize` and `document.exportSelection`
accept a key that only another format takes. `{"format": "pdf",
"quality": 80}` wrote the PDF and gave no warning about `quality`.

The reply's `warnings` now name each such key, in the wording of a
save's note: "`quality` was not used: PDF files don't read it".

- The format's own options, the commands' own keys, null values and an
  exporter plug-in's format get no note.
- The note names the kind of file written. A legacy `.ai` file
  (`aiVersion: "7"`) reads `outlineText`, `hiddenObjects`,
  `transparentImages`, the artboard choice and `useArtboards`, and
  beside `aiVersion` no other option. The other `.ai` files don't read
  those three options or `preserveEditing`, which is always on for
  them.
- An export doesn't read `separateArtboards`, or `range` for a
  `vectorcraft` or `template` file. A save reads them to write each
  artboard to a file of its own.
- In the app, an export that automation asked for (`app.export` with a
  path, `file.exportAs` run as a command) gives the same notes in its
  reply and in the status bar. A Background Export replies before the
  file is written, and that reply has the notes. An export that a
  person starts from the File menu gets none.
- Export As gives a template export no `useArtboards` or `range`: a
  template doesn't read them.
- `vectorcraft-cli convert` sends `outlineText` only with
  `--outline-text`, and `hiddenLayers` only to the formats that read
  it. A conversion then warns only about an option the command line
  gave.

`document.save` gives its notes as before: it does not apply the `.ai`
rules above.

Docs: docs/mcp.md, docs/control-protocol.md,
docs/target-app-parity.md, the params text of the three commands.

docs/control-protocol.md

@@ -107,7 +107,7 @@ the two can still win that race.
 | `ui.render` | `{path?, scale?, artboard?, data?, traceViews?}` | render an artboard headlessly (PNG with the pixels of `app.export {format: "png", background: "white"}` at the same scale; `artboard`: its 0-based index, default the first; `traceViews: true`: Image Trace objects draw in their View, as on the canvas, instead of their tracing result): written to `path`, else (or with `data: true` as well) sent back as `pngBase64` |
 | `ui.render` | `{path?, scale?, artboard?, data?}` | render an artboard headlessly (PNG with the pixels of `app.export {format: "png", background: "white"}` at the same scale; `artboard`: its 0-based index, default the first): written to `path`, else (or with `data: true` as well) sent back as `pngBase64` |
 | `ui.resize` / `ui.focus` | | |
-| `app.open` / `app.save` / `app.export` / `app.quit` | `{path, importer?, params?}` / `{path?}` / `{path?, format?, artboard?, range?, scale?, …}` | `app.open` reads every format `document.open` reads (see `document.formats`) and returns its result (`{index, title, format, warnings, …}`; `warnings` say what didn't come in as it was, such as an EPS shown as its preview image and why its PostScript couldn't be read), or null when a dialog asks first or a library loads. The status bar (`ui.inspect` → `ui.status`) counts the `warnings` and names the first that says reading the file left something out (the notes that make Save ask before writing over it), else the first; with several, hovering it lists them in that order, as many as fit in the window (at most 30), then how many more. After `app.save`, and `app.export` with a `path`, the status bar counts the reply's `warnings` and names the first, and with several, hovering it lists them in the reply's order (a save's notes start with what the format loses). With `importer` (an importer plug-in's format id, `plugin.<id>`) it runs `file.openWith`: the file opens with that importer, also when a built-in format reads its extension, with the importer's parameters `params` (their defaults when omitted; no dialog asks for them). Without `importer`, `params` go to the importer that opens the file, and a built-in format does not read them. `app.export` encodes through the engine's `document.export` (same options; the document keeps its path) and writes `path` through the host; without `path` it returns `{dataBase64, format, bytes}`, as headless mode does. It refuses a key that no format takes, and an unknown key inside a PDF or EPS option object, before it writes anything (`docs/mcp.md`, Parameter keys). `app.save` refuses a key that no save format takes, beside the path or in `options`, the same way. `app.quit`, `file.close` and `file.closeAll` first open a `saveChanges` dialog for each modified document (they return `{"pending": "saveChanges"}`): `ui.dialog.confirm` saves, `ui.dialog.set {field: "discard", value: true}` then confirm discards, `ui.dialog.cancel` cancels the whole close or quit |
+| `app.open` / `app.save` / `app.export` / `app.quit` | `{path, importer?, params?}` / `{path?}` / `{path?, format?, artboard?, range?, scale?, …}` | `app.open` reads every format `document.open` reads (see `document.formats`) and returns its result (`{index, title, format, warnings, …}`; `warnings` say what didn't come in as it was, such as an EPS shown as its preview image and why its PostScript couldn't be read), or null when a dialog asks first or a library loads. The status bar (`ui.inspect` → `ui.status`) counts the `warnings` and names the first that says reading the file left something out (the notes that make Save ask before writing over it), else the first; with several, hovering it lists them in that order, as many as fit in the window (at most 30), then how many more. After `app.save`, and `app.export` with a `path`, the status bar counts the reply's `warnings` and names the first, and with several, hovering it lists them in the reply's order (a save's notes start with what the format loses). With `importer` (an importer plug-in's format id, `plugin.<id>`) it runs `file.openWith`: the file opens with that importer, also when a built-in format reads its extension, with the importer's parameters `params` (their defaults when omitted; no dialog asks for them). Without `importer`, `params` go to the importer that opens the file, and a built-in format does not read them. `app.export` encodes through the engine's `document.export` (same options; the document keeps its path) and writes `path` through the host; without `path` it returns `{dataBase64, format, bytes}`, as headless mode does. It refuses a key that no format takes, and an unknown key inside a PDF or EPS option object, before it writes anything (`docs/mcp.md`, Parameter keys). It accepts a key that only another format takes and does not use it: the reply's `warnings` and the status bar name the key ("`quality` was not used: PDF files don't read it"). `app.save` refuses a key that no save format takes, beside the path or in `options`, the same way. `app.quit`, `file.close` and `file.closeAll` first open a `saveChanges` dialog for each modified document (they return `{"pending": "saveChanges"}`): `ui.dialog.confirm` saves, `ui.dialog.set {field: "discard", value: true}` then confirm discards, `ui.dialog.cancel` cancels the whole close or quit |
 | `app.export` with `useArtboards` | `{path, useArtboards: true, range? \| artboards?, …}` | Export As: PNG, JPEG and WebP write one file per chosen artboard (default all; SVG does so for a `range`), `<path stem>-<artboard>.<ext>`, and return `{path, files: [path…]}`; a PDF keeps them as pages of `path`. `useArtboards: false` covers the bounds of the visible art. The menu's Export As… is `file.exportAs`: the `exportAs` dialog (`format`, `useArtboards`, `all`, `range`), then a save dialog and the format's options: `pngOptions` / `jpgOptions` / `webpOptions`, `svgOptions`, or `savePdf` for a PDF |
 | `ui.dialog.*` on `gradientStop` | `{field: "color" \| "opacity" \| "location", value}` | double-clicking a stop on the Gradient tool's annotator opens its popover (fields `index`, `x`, `y`, `tab`); set `color` (hex), `opacity` or `location` (percentages) and `ui.dialog.confirm` to apply them to the selected stop. `gradient.selectStop {index}` picks the stop the annotator, the panels and Delete/←/→ (`ui.key`) act on |
 | `engine.execute` `ui.savePdfDialog` | `{path?, preset?, range?, …document.exportPdf options}` | opens the Save PDF dialog (`file.export.pdf` with no params opens it too). Its fields are the `document.exportPdf` options: set `compatibility` with `ui.dialog.set {field: "compatibility", value: "1.5"}`, a whole section with `{field: "compression", value: {…}}`, the artboards with `__allArtboards: false` and `range`, the visible section with `__section` (General, Compression, Marks and Bleeds, Output, Advanced, Security, Summary). `useArtboards: false` opens it for one page of the visible art's bounds, as Export As with Use Artboards off does: the dialog has no Artboards section and its `__artBounds` field is true. `ui.dialog.confirm` writes `path` (else asks for one), returns `{path, bytes, warnings}` and opens the file when `viewAfterSaving` is set. With `useArtboards: false` it writes the page as `app.export` does and returns `{path, warnings}`, or `{background: true, status}` while Background Export writes it |
@@ -120,7 +120,7 @@ the two can still win that race.
 | `app.export` Text and WebP | `{path?, format: txt, encoding?: utf8 \| utf16, lineEndings?: lf \| crlf, selectionOnly?}` / `{format: webp, lossless?, quality?}` | Text writes the stories in stacking order (back to front; a thread once; hidden objects and template layers left out), each line ended by `lineEndings`; `utf16` is little-endian with a byte order mark. Export As → Text opens `txtOptions` (fields `path`, `encoding`, `lineEndings`, `selectionOnly`; OK writes the file). WebP is always lossless: `lossless: false` adds a warning |
 | `engine.execute` `document.exportForOffice` | `{}` / `{path?, ppi?: 72 \| 150 \| 300, transparent?, artboard?}` | File → Save for Office Documents…: without params opens `saveForOffice` (fields `ppi`, `transparent`, `artboard`; OK picks the file); with params writes the artboard as a PNG (`path`, else a picked file) → `{path}`, and the status bar shows the export's `warnings` as Save As shows a save's notes. Headless it returns `{dataBase64, width, height, warnings}` |
 | Native file dialogs | any command with no `path` that needs one (`file.open`, `file.saveAs`, `file.place`, exports…) | on macOS (a sheet on the window) and Linux the dialog doesn't hold the window: the call returns `"cancelled"` at once, `ui.inspect` reports `fileDialog`, and when the person at the computer picks a file the command runs again on the document it was asked for. While it is open another dialog is refused: that call returns `"cancelled"` too, and the status bar (`ui.inspect` → `ui.status`) says `"A file dialog is open: choose there first"`; on macOS `app.quit`, `file.close` and `file.closeAll` return that message and the menu bar does nothing (#592, #867). On Windows the dialog is shown in line: the call returns once it closes. Pass `path` to skip the dialog |
-| Background Save / Export | `app.save`, `app.export {path}`, `file.save`, `file.saveAs`, `file.saveCopy`, `file.exportForScreens {folder, …}` | with the `backgroundSave` / `backgroundExport` preferences on (the default) the desktop app writes the file from a snapshot on a worker thread: the call returns `{path, background: true, status}` at once (`file.exportForScreens`: `{background: true, status}`, and the files are written into the folder from a snapshot taken at the call), `ui.inspect` lists the jobs still running in `background` (labels such as `"Saving a.vectorcraft"`), and the document counts as saved (as of the snapshot) once its file is written. Quit and Close wait for them. A job that fails reports the error in the status bar only (`ui.inspect` → `ui.status`), a path outside `--automation-write-root` included. With the preferences off (`prefs.set`), saves return once written. `app.save {path?, wait: true}` and `app.export {path, wait: true}` wait for the jobs already running, write the file before they reply whatever the preferences are set to, and return its result or the error. When the save asks first (the question before replacing a file that opened with losses, or on macOS and Linux the file dialog for an untitled document without `path`), the reply is `{pending}` or `"cancelled"` as before, and the save that runs after the answer uses the preferences. A `wait` that is not `true`, `false` or `null` is refused with "`wait` must be true or false", and nothing is written |
+| Background Save / Export | `app.save`, `app.export {path}`, `file.save`, `file.saveAs`, `file.saveCopy`, `file.exportForScreens {folder, …}` | with the `backgroundSave` / `backgroundExport` preferences on (the default) the desktop app writes the file from a snapshot on a worker thread: the call returns `{path, background: true, status}` at once (`file.exportForScreens`: `{background: true, status}`, and the files are written into the folder from a snapshot taken at the call; an `app.export` given an option the format doesn't read: also `warnings`, naming the option), `ui.inspect` lists the jobs still running in `background` (labels such as `"Saving a.vectorcraft"`), and the document counts as saved (as of the snapshot) once its file is written. Quit and Close wait for them. A job that fails reports the error in the status bar only (`ui.inspect` → `ui.status`), a path outside `--automation-write-root` included. With the preferences off (`prefs.set`), saves return once written. `app.save {path?, wait: true}` and `app.export {path, wait: true}` wait for the jobs already running, write the file before they reply whatever the preferences are set to, and return its result or the error. When the save asks first (the question before replacing a file that opened with losses, or on macOS and Linux the file dialog for an untitled document without `path`), the reply is `{pending}` or `"cancelled"` as before, and the save that runs after the answer uses the preferences. A `wait` that is not `true`, `false` or `null` is refused with "`wait` must be true or false", and nothing is written |
 | `engine.execute` `file.exportForScreens` | `{}` / `{…document.exportForScreens params}` | without params opens `exportForScreens` on the settings the document last exported with (`document.exportSettings`). While the Artboard tool is in use, the artboards it has selected (its `selected` option, the rows the Artboards panel highlights) are checked instead, and `select` is `range`, or `all` when every artboard is selected. Fields: `tab` (`artboards` \| `assets` \| `layers` \| `selection`; OK reads Export Layer or Export Selection on those), `layers` ([layer id…] checked), `selectionMode` (`one` \| `each`), `name` (the file name pattern of `document.exportForScreens`), `counterStart`, `folders` (`none` \| `rows` \| `format` \| `item` \| `itemFormat`), `exportPreset` (the preset applied last), `__savePreset` (the name typed to save one), `select` (`all` \| `range` \| `full`), `range` ("1-3, 5"), `boards` (a bool per artboard; checking them sets `select` and `range`), `includeBleed`, `folder` (desktop; default the Desktop, else home), `openLocation`, `subfolders`, `prefix`, `preset` (`""` \| `mobile` \| `density`), `formats` (rows `{format, scale: "2x" \| "100w" \| "100h" \| "72ppi", suffix, quality?, folder?}`), `settings` (`{png \| png8 \| jpg \| webp \| gif \| svg \| pdf: {…options}}`, the gear's Format Settings; `__settings` names the format shown). `ui.dialog.confirm` exports (a bad range or no folder keeps it open); on the web OK reads "Download" and the files download (several as one `.zip`). With params it runs `document.exportForScreens`: no `folder` returns the files (or with `zip: true` one zip) as `dataBase64`; with `openLocation` the first file is shown in the file manager. When `warnings` is not empty, an export into a folder or a download shows the first in the status bar as Save As shows a save's notes |
 | Export for Screens' Assets tab, Asset Export panel | `ui.dialog.set` `tab: "assets"`, `assets: [asset id…]`; `window.panel {panel: "assetExport"}` | on the Assets tab of `exportForScreens` the `assets` field lists the checked asset ids (all of them when it opens); `ui.dialog.confirm` runs `document.exportForScreens {assets}` (nothing checked keeps it open) and OK reads "Export Asset". The Asset Export panel acts through `assets.*` and shares the format rows with the dialog (`assets.settings.set`). The dialog has the format presets menu (☰). In the dialog, `exportPreset` names the preset applied last (`ui.dialog.set` of it applies the preset it names, as picking it does; a name that is not a preset's is an error and leaves the dialog as it was), `__exportPresets` lists the presets, and `__savePreset` holds the name being typed after Save Preset…. The panel menu applies presets through `assets.settings.set {exportPreset}` and holds Save As Preset…, Save Changes, Delete Preset, Import Preset… and Export Preset…. Import and Export use picked files. |
 | `engine.execute` `file.exportSelection` | `{multiple?}` | File › Export Selection…: collects the selected objects as one asset (`assets.add`; one per object with `multiple: true`) and opens `exportForScreens` on its Assets tab with just them checked → `{assets}`. `document.exportSelection` still exports the selection in one go, without the dialog |

docs/mcp.md

@@ -1574,8 +1574,18 @@ hides the dock, no panel is checked, and the panel shows again with the dock in
 Control bar stay as they are.
 
 The export commands limit those keys. `document.export`, `document.exportSelection`, `document.serialize`, `app.export`
-and `file.export` refuse a key that no format takes, and ignore a key that only another format takes
-(`{"format": "pdf", "quality": 80}` writes the PDF). `document.exportPdf`, `document.pdfSettings` and `pdf.preset.save`
+and `file.export` refuse a key that no format takes. They accept a key that only another format takes and do not use
+it: `{"format": "pdf", "quality": 80}` writes the PDF, and the reply's `warnings` name the key
+("`quality` was not used: PDF files don't read it"), in the wording of a save's note. The warning names the kind of
+file written. A legacy `.ai` file (`aiVersion: "7"`) reads `outlineText`, `hiddenObjects`, `transparentImages`, the
+artboard choice and `useArtboards`, and beside `aiVersion` no other option
+("`compress` was not used: legacy .ai (version 7) files don't read it"). The other `.ai` files don't read those three
+options or `preserveEditing`, which is always on for a `.ai` file. An export doesn't read `separateArtboards`, or
+`range` for a `vectorcraft` or `template` file: a save reads them to write each artboard to a file of its own. In the
+desktop app, `app.export` and `file.exportAs` give these warnings in the reply and the status bar
+when automation asked for the export. An `app.export` that returns before the file is written (`background: true`)
+gives them in that reply. An export that first asks a question (the one before replacing a file) and that a person
+then answers gives none. `document.exportPdf`, `document.pdfSettings` and `pdf.preset.save`
 refuse a key that PDF doesn't take, `document.exportEps` one that EPS doesn't take and `document.exportDxf` one that DXF
 doesn't take. Each of them refuses an unknown key inside an option object it takes (`marks`, `bleed`, `compression`,
 `output`, `advanced`, `security`, `flattener`, `svg`), naming its path:

docs/target-app-parity.md

@@ -869,7 +869,7 @@ Moved from the ROADMAP's "Shipped so far" on 2026-10-10. Update it when a featur
   - The errors of the 3D effects (Extrude & Bevel, Revolve, Inflate, Rotate and their Classic forms) show in the status bar in the interface language: the art a 3D effect cannot build a solid from, invalid light, graphics and surface settings, and the notes for an object that draws no 3D faces or more wireframe edges than the limit. Each has a row in every catalog that translates all status and error messages, and the effect's name and the values in the message are translated or kept as written (`three_d_refusals_are_translated_in_every_complete_catalog`, `three_d_refusals_translate_with_their_values`).
   - The errors of the parameter checks that many commands share show in the status bar in the interface language: a value that is not a number where a number goes (`object.move` with `"dx": "60 mm"`, and `object.rotate`, `object.setBounds` and the other commands that call `check_numbers`), a missing number or index, `ids` that are not a list of object ids, an object id that is not a non-negative integer or names no object, and a date that is not Unix seconds. Each has a row in every catalog that translates all status and error messages, and in Bulgarian, Danish, Indonesian and Dutch (`shared_param_check_errors_are_translated`).
   - A parameter schema's errors show in the status bar with what the value must be in the interface language, for every type a schema has (a number with each kind of range and with a unit, an integer and its range, true or false, a string, a list of names, an object id, a list of object ids, a color, a point, an object and a list), in every catalog that translates all status and error messages; the path, the refused value, the bounds, the unit and the names stay as the English gives them. The error for a value that is not one of its names is also translated in Bulgarian, Bosnian, Danish, Indonesian and Dutch (`parameter_schema_expected_phrases_are_translated`, `bracketed_message_parts_translate_only_as_exact_messages`).
-  - Export commands run through MCP, the control channel or the CLI refuse a key that no format takes, and a command that writes one format (`document.exportPdf`, `document.exportEps`, `document.exportDxf`) or takes one format's options (`document.pdfSettings`, `pdf.preset.save`) refuses a key that format doesn't take. An unknown key inside `marks`, `bleed`, `compression`, `output`, `advanced`, `security` or `flattener` is refused by its path.
+  - Export commands run through MCP, the control channel or the CLI refuse a key that no format takes, and warn about a key that only another format takes (`{"format": "pdf", "quality": 80}` writes the PDF with the warning "`quality` was not used: PDF files don't read it"; `an_option_only_another_format_reads_gets_a_note`, `control_export_notes_an_option_the_format_does_not_read`, `convert_warns_about_an_unused_option_only_when_one_was_given`), and a command that writes one format (`document.exportPdf`, `document.exportEps`, `document.exportDxf`) or takes one format's options (`document.pdfSettings`, `pdf.preset.save`) refuses a key that format doesn't take. An unknown key inside `marks`, `bleed`, `compression`, `output`, `advanced`, `security` or `flattener` is refused by its path.
   - Save commands run through MCP, the control channel or the CLI (`document.save`, `file.saveAs`, `file.saveCopy`, `file.saveAsTemplate`, `app.save`) refuse a key that no save format takes, beside the path or in `options`. Export for Screens refuses a key it doesn't take, and a key that no format takes in a format row or in a format's settings, by its path (`formats[1].marks.useDocumentBleed`); Export Assets (`assets.export`, `assets.settings.set`) checks the rows and settings it is given the same way.
   - Commands that read their `ids` (or `slices`) list themselves refuse a list with an entry that is not a non-negative integer, and a value that is not a list, and change nothing; they no longer drop the entry and act on the rest (Copy Appearance From, the Edit Colors commands and Overprint Black, Find and Replace, `layer.highlight`, `layer.move`, `library.add`, the Links panel commands, `object.transform`, Make Pattern, the Repeat commands, the slice commands, Join, Average and Join, `plugin.run`, `symbol.edit`, Make Opacity Mask; `tests::ids_without_selection::an_ids_entry_that_is_not_an_id_is_refused_and_changes_nothing`). The error for an entry of an object id list names the key, the entry and its value ("`ids` entry 1 is true, not a non-negative integer object id"), with a row in every catalog that has the other object id errors.
   - The errors of Enter Isolation Mode (`object.isolate`) for a type object, for hidden or locked art and for a call with no `id` while nothing is selected ("missing id", which other commands that take an `id` also give), and the error of the Layers panel's target circle (`layer.target`) for an object outside the isolated group, show in the status bar in the interface language: each has a row in every catalog that translates all status and error messages, and in Bulgarian, Danish, Indonesian and Dutch.