M1: reconcile tab drag with upstream and document transfer contracts

docs/development.md

@@ -439,6 +439,7 @@ Scores and hour estimates are unchanged.
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-22 | minor | Tab-drag follow-up: reconcile upstream progress updates and document drag lifecycle, insertion behavior and regression contracts; behavior, scores and estimates unchanged. |
 | 2026-10-22 | minor | Artwork dragged with Selection switches visible document tabs after a 400 ms hover, then copies editable artwork on canvas release; source and clipboard stay intact; scores and hours unchanged |
 | 2026-10-21 | minor | M3: highlighted-text Eyedropper sampling preserves ranges and rejects unsupported source/target transparency atomically; regression-tested; scores and estimates unchanged. |
 | 2026-10-21 | minor | Fonts › Leaving out the bundled fonts: vectorcraft-ui-egui's and vectorcraft-mcp's `bundled-fonts` features, and the engine declared without default features. |

docs/mcp.md

@@ -615,6 +615,8 @@ Images follow the `compression` settings of their kind (`color`, `gray`, or `mon
 `abovePpi` as placed they are resampled (`downsample`: `average`, `subsample` or `bicubic`) to `ppi`, and compressed
 with `zip`, `jpeg` (at `quality`; images with transparency stay lossless) or `auto` (JPEGs stay JPEG, the others
 lossless). `none`, `jpeg2000`, CCITT and `runLength` are written as ZIP, with a warning when an image needs them.
+A 16-bit PNG that is not resampled, recompressed or converted keeps its 16 bits a sample in PDF 1.5 and later files,
+and is written at 8 bits in PDF 1.3 and 1.4 files.
 CMYK images stay CMYK (DeviceCMYK, or ICC-based with the CMYK profile when colours are tagged, as in PDF/X-3 and
 PDF/X-4): a CMYK JPEG neither resampled nor recompressed is written unchanged, and the others' ink amounts are
 resampled and compressed again (CMYK JPEG or ZIP). `output.conversion` converts them like CMYK colours: `destination`
@@ -732,9 +734,9 @@ PostScript form, which keeps layers, groups, compound paths and clipping groups
 of `range` (default all; `{name}-{artboard}.ai` when several, listed in the result's `files`), with
 `transparentImages: "flatten"` (default) or `"omit"` for images with see-through pixels, opacity or a blending mode,
 `hiddenObjects: "layer"` (default: a hidden layer of each layer's hidden objects), `"omit"` or `"visible"`, and
-`outlineText: true` to write type as outlines instead of text objects. When an image in art that is flattened or whose
-raster effects are expanded can't be decoded, the result does not show it, and `warnings` carries "an image couldn't
-be decoded and is missing from the picture" once. From the CLI: `vectorcraft-cli convert in.svg
+`outlineText: true` to write type as outlines instead of text objects. An image that can't be decoded is left out of
+the file and does not show in art that is flattened or whose raster effects are expanded; `warnings` carries "an image
+couldn't be decoded and is missing from the picture" once for all such images. From the CLI: `vectorcraft-cli convert in.svg
 out.ai --ai-version 7 [--hidden-objects layer|omit|visible] [--transparent-images flatten|omit] [--outline-text]
 [--range R]`. `document.export`, `serialize`, `exportSelection` and `exportForScreens` refuse a `.ait` path or
 `format: "ait"` with an error that names `file.saveAsTemplate`, which writes it. The CLI's `run --export x.ait` and
@@ -3205,7 +3207,9 @@ width profiles, arrowheads) as filled outlines; `"editability"` keeps type as te
 `alterPaths` writes every stroke as its filled outline, `outlineText` outlines type, `selectedOnly` writes only the
 selected objects in their layers (every export takes it), and `useArtboards: true` writes one drawing per chosen
 artboard holding the art over it. What DXF can't hold (gradients and patterns as one colour, blending, opacity masks,
-raster effects, clipping) comes back in `warnings`.
+raster effects, clipping) comes back in `warnings`. In R13 and later, an image that can't be decoded is left out with
+no linked file, and `warnings` carries "an image couldn't be decoded and is missing from the picture" once for all such
+images.
 
 DWG can't be written (no openly licensed writer exists): `document.formats` lists it under `unsupported` with that
 hint, and exporting to it answers with the hint to export DXF. PICT files are not supported either and say so when
@@ -3378,7 +3382,9 @@ per artboard, `{stem}_{artboard}.eps`, each bounded by its artboard. `level: 3`
 shadings and masks transparent image pixels out; `level: 2` writes gradients as bands of colour (as does
 `compatibleGradients`) and transparent pixels white. Type is always glyph outlines, so no fonts are needed (`embedFonts`
 is accepted); spot colours are Separation colour spaces, and overprinting fills and strokes overprint unless
-`overprints: "discard"`. RGB documents are written in CMYK unless `cmykPostScript: false`.
+`overprints: "discard"`. RGB documents are written in CMYK unless `cmykPostScript: false`. When the file would hold an
+image that can't be decoded, the image is left out, and `warnings` carries "an image couldn't be decoded and is missing
+from the picture" once for all such images.
 
 PostScript has no transparency: it is flattened first with `flattenerPreset` (`high`, `medium` (default), `low` or a
 saved preset, see `flattener.presets.list`) and `flattener: {…}` options over it (those of
@@ -3511,7 +3517,9 @@ outlines; gradients become images clipped to their shape, pattern fills their ti
 effects images rendered at the document's raster effects resolution. The header's frame is the artboard in 0.01 mm.
 WMF flattens curves into polygons in 16-bit units behind a placeable header (1440 units an inch, fewer for pictures
 over about 22 inches); it has no clipping, transparency or gradients, so clipped art is written whole, images over
-white and gradients and patterns as one colour. What a format leaves out comes back in `warnings`.
+white and gradients and patterns as one colour. What a format leaves out comes back in `warnings`. When the picture
+would hold an image that can't be decoded, the image is left out, and `warnings` carries "an image couldn't be decoded
+and is missing from the picture" once for all such images.
 
 `document.open` and `file.place` read `.emf` and `.wmf` (placeable or not) into one artboard, the picture's frame, and
 one layer: paths with their fills and strokes (pens become strokes with caps, joins and dashes), clipping groups,
@@ -4144,6 +4152,25 @@ explicitly, `{}` for none. Each command is one undo step.
 {"name":"run_command","arguments":{"command":"text.setFormat","params":{"fontAxes":{"wght":650,"wdth":87.5}}}}
 ```
 
+## Character Direction
+
+`text.setFormat {charDirection: "default"|"leftToRight"|"rightToLeft"}` (the selected type, or `ids`) and
+`text.setRangeStyle {id, start, end, charDirection}` (a range) set the direction of the characters inside their
+paragraph, as the Character panel menu's Character Direction does with the Middle Eastern (Indic) options shown. The bidi
+algorithm (UAX #9) resolves each stretch of characters with a direction as an embedding in that direction, as if an LRE
+or RLE stood before it and a PDF after it: `leftToRight` keeps a date written with spaces, such as `21 10 2026`, in its
+order inside a right-to-left paragraph, and `rightToLeft` sets a Hebrew or Arabic word and the punctuation after it right
+to left inside a left-to-right paragraph. Characters keep their own strong direction inside an embedding: Latin letters
+set Right to Left still read left to right. `default` leaves the characters to the bidi algorithm. The paragraph's own
+direction is unchanged. SVG export writes type with a character drawn right to left, or with a run set Right to Left,
+as outlines; live SVG text writes `direction="ltr"` and `unicode-bidi="embed"` on each run set Left to Right. Character
+Direction is Default until set and is saved only when set, and character styles captured from type carry it. Each
+command is one undo step.
+
+```json
+{"name":"run_command","arguments":{"command":"text.setRangeStyle","params":{"id":12,"start":9,"end":19,"charDirection":"leftToRight"}}}
+```
+
 ## Digits
 
 `text.setFormat {digits: "default"|"arabic"|"hindi"|"farsi"}` (the selected type, or `ids`) and `text.setRangeStyle {id,