fix: a frame is alone on its line, not only on its block

The no-descent rule matched a block holding nothing but frames, so the
image-break-caption idiom kept a text descent under its picture — 0.9mm
per figure, and LibreOffice's own guides stack dozens of them in tables.
Test the run between two hard breaks instead and mark the frame itself.

docs/architecture/frames.md

@@ -3,5 +3,5 @@
 Covers `src/lib/editor/extensions/image.ts` and `textBox.ts` — node views, resize/rotate
 handles, wrap modes, frame offsets — and their ODF/DOCX legs.
 
-- **`image.ts`** (`Image`) — inline, as-character image atom (Word's "in line with text"). Attrs: `src` (data-URI), `alt`, `width`/`height` (**unscaled doc px @96dpi**, like `rowHeight`), `rotation` (CW degrees). The node view nests an `<img>` in a rotated "rotor" inside an axis-aligned wrapper that reserves the rotated bounding box (so text reflows around it). The rotor's transform makes it a stacking context, so a selected `.image-node` is given a `z-index` above the header/footer layer to keep handles that poke into a margin grabbable. It has eight zoom-aware resize handles — corners aspect-locked, edges single-axis (width- or height-only) — plus a rotation-arrow grip, and shows a live "Width … × Height …" (cm) badge while resizing; resize deltas are un-rotated onto the image's own axes so handles track the pointer at any angle (drag math mirrors `tableRowResize.ts`; width cap = the cell or page-text-column, height cap = the page text height). `setImage` command inserts it; the toolbar button (ToolbarExpanded), drag-drop and paste (Editor.svelte) read the file via `FileReader` → data-URI and clamp the initial size to the page text box. **Text wrap:** the `wrap` attr (`'inline'|'left'|'right'|'topBottom'`) makes the image a *floating* frame — `ImageToolbar.svelte` (a per-image floating toolbar wired in `Editor.svelte` like `TableToolbar`) sets the mode; `left`/`right` float the wrapper at its anchor paragraph (text flows on the open side via CSS `float`), `topBottom` is a **full-width `float`** (text only above/below). All modes use `float` deliberately: an in-flow `display:block` on an inline-atom node view splits the paragraph's inline content into anonymous block boxes, which desyncs ProseMirror's inline view descriptor and makes it drop the following page-break spacer widget; a float is out-of-flow and avoids that. Dragging an **inline** image runs ProseMirror's native node move (the `dropCursor` plugin shows the caret). Dragging a **floating** image runs a custom drag (`ImageView.startReposition`) that **live re-anchors** the node to the text position under the cursor, so the float and text reflow in real time as you drag; it's rAF-throttled and only moves when the cursor's line changes (a float can't move within a line), and stays a single undo step (first move records history, later moves are `addToHistory:false` and get rebased on undo). A paragraph that contains an image paginates **atomically** (`pageBreaks.ts` — pushed whole to the next page, spacer placed before it) so a page break never splits the paragraph next to the image's float (where ProseMirror drops the spacer widget). **Wrap distance:** a float reserves 14px beside itself and **nothing above or below** — LibreOffice and Word both wrap flush against a frame unless the file declares a distance, and 6px of our own put every figure in a text box 3mm too tall. **Vertical alignment (as-char):** `vAlign` carries ODF's `style:vertical-pos`/`-rel` pair for an inline frame — `null` (LibreOffice's `top`/`baseline` and Word's only mode) stands the frame on the text baseline, `middle`/`below` centre it on the baseline or hang it below, and `text-top`/`text-middle`/`text-bottom` measure against the character area instead (CSS `vertical-align: text-top`/`text-bottom`; nothing in CSS centres on that area, so `text-middle` uses 0.36em for half of ascent − descent, which Liberation Serif/Sans, Times and Arial share). `from-top` becomes `vAlign: 'offset'` and puts the frame's top `wrapOffsetY` cm below the baseline whatever the relation says — all probed against LibreOffice, whose formula images use `middle`/`text` and `from-top` almost exclusively. A line an as-char frame has to itself — nothing beside it but whitespace — is as tall as the frame or the block's line height, whichever is more, with **no text descent below it** (probed); the block carries an `image-line` class from `image.ts` for it, since CSS cannot ask whether a line holds real text. A frame that shares its line with text keeps the baseline and the descent. **Frame offsets:** `wrapOffset` is the frame's left edge in the text column (Word's `positionH` posOffset, ODF `svg:x`), rendered as the float's near/far margin against the live column vars — an indented anchor paragraph can't skew it — and shared with `textBox.ts` through `frameMargins`. A `topBottom` float spans the column, so its own x moves the *rotor* inside the wrapper instead. `wrapOffsetY` (`positionV`, `svg:y`) is the frame's top below the anchor paragraph's, drawn for `topBottom` only — no text sits beside such a frame, where a side float's top margin would push away lines Word keeps. Chromium places **every** line after a full-width float below it, even the ones the float's top margin leaves room for, so a frame set below the paragraph top is sunk behind that paragraph's text at import (`sinkOffsetFrames`, both importers) and `ImageView.sinkToOffset` measures what the lines above it alrLine truncated
+- **`image.ts`** (`Image`) — inline, as-character image atom (Word's "in line with text"). Attrs: `src` (data-URI), `alt`, `width`/`height` (**unscaled doc px @96dpi**, like `rowHeight`), `rotation` (CW degrees). The node view nests an `<img>` in a rotated "rotor" inside an axis-aligned wrapper that reserves the rotated bounding box (so text reflows around it). The rotor's transform makes it a stacking context, so a selected `.image-node` is given a `z-index` above the header/footer layer to keep handles that poke into a margin grabbable. It has eight zoom-aware resize handles — corners aspect-locked, edges single-axis (width- or height-only) — plus a rotation-arrow grip, and shows a live "Width … × Height …" (cm) badge while resizing; resize deltas are un-rotated onto the image's own axes so handles track the pointer at any angle (drag math mirrors `tableRowResize.ts`; width cap = the cell or page-text-column, height cap = the page text height). `setImage` command inserts it; the toolbar button (ToolbarExpanded), drag-drop and paste (Editor.svelte) read the file via `FileReader` → data-URI and clamp the initial size to the page text box. **Text wrap:** the `wrap` attr (`'inline'|'left'|'right'|'topBottom'`) makes the image a *floating* frame — `ImageToolbar.svelte` (a per-image floating toolbar wired in `Editor.svelte` like `TableToolbar`) sets the mode; `left`/`right` float the wrapper at its anchor paragraph (text flows on the open side via CSS `float`), `topBottom` is a **full-width `float`** (text only above/below). All modes use `float` deliberately: an in-flow `display:block` on an inline-atom node view splits the paragraph's inline content into anonymous block boxes, which desyncs ProseMirror's inline view descriptor and makes it drop the following page-break spacer widget; a float is out-of-flow and avoids that. Dragging an **inline** image runs ProseMirror's native node move (the `dropCursor` plugin shows the caret). Dragging a **floating** image runs a custom drag (`ImageView.startReposition`) that **live re-anchors** the node to the text position under the cursor, so the float and text reflow in real time as you drag; it's rAF-throttled and only moves when the cursor's line changes (a float can't move within a line), and stays a single undo step (first move records history, later moves are `addToHistory:false` and get rebased on undo). A paragraph that contains an image paginates **atomically** (`pageBreaks.ts` — pushed whole to the next page, spacer placed before it) so a page break never splits the paragraph next to the image's float (where ProseMirror drops the spacer widget). **Wrap distance:** a float reserves 14px beside itself and **nothing above or below** — LibreOffice and Word both wrap flush against a frame unless the file declares a distance, and 6px of our own put every figure in a text box 3mm too tall. **Vertical alignment (as-char):** `vAlign` carries ODF's `style:vertical-pos`/`-rel` pair for an inline frame — `null` (LibreOffice's `top`/`baseline` and Word's only mode) stands the frame on the text baseline, `middle`/`below` centre it on the baseline or hang it below, and `text-top`/`text-middle`/`text-bottom` measure against the character area instead (CSS `vertical-align: text-top`/`text-bottom`; nothing in CSS centres on that area, so `text-middle` uses 0.36em for half of ascent − descent, which Liberation Serif/Sans, Times and Arial share). `from-top` becomes `vAlign: 'offset'` and puts the frame's top `wrapOffsetY` cm below the baseline whatever the relation says — all probed against LibreOffice, whose formula images use `middle`/`text` and `from-top` almost exclusively. A line an as-char frame has to itself — nothing beside it but whitespace — is as tall as the frame or the block's line height, whichever is more, with **no text descent below it** (probed); `image.ts` gives such a frame an `image-line` class, since CSS cannot ask whether a line holds real text. Hard breaks are the only line boundaries the model shows, so the run between two of them is what gets tested — which covers the frame-break-caption idiom LibreOffice's own guides are full of; a frame alone on a *soft-wrapped* line is invisible from there. A frame that shares its line with text keeps the baseline and the descent. **Frame offsets:** `wrapOffset` is the frame's left edge in the text column (Word's `positionH` posOffset, ODF `svg:x`), rendered as the float's near/far margin against the live column vars — an indented anchor paragraph can't skew it — and shared with `textBox.ts` through `frameMargins`. A `topBottom` float spans the column, so its own x moves the *rotor* inside the wrapper instead. `wrapOffsetY` (`positionV`, `svg:y`) is the frame's top below the anchor paragraph's, drawn for `topBottom` only — no text sits beside such a frame, where a side float's top margin would push away lines Word keeps. Chromium places **every** line after a full-width float belowLine truncated
 - **`textBox.ts`** (`TextBox`) — block-level text box / basic shape with editable block content (`content: '(paragraph|heading|bulletList|orderedList)+'`, `isolating`). Attrs: `width`/`height` (px @96dpi; height renders as **min-height** — content grows the box), `rotation` (CW deg), `wrap` (image's `WrapMode`; `inline` renders in-flow, floats via CSS `float` like `ImageView.applyWrap`), `shapeKind` (`'textbox'|'roundRect'|'ellipse'` — ellipse renders via `border-radius:50%`), `fillColor`/`strokeColor` (`null` = transparent/no border), `strokeWidthPt`. Padding is the fixed `TEXTBOX_PADDING_CM` (0.15cm). The node has its **own group** (`group: 'textBox'`) so only the document admits it (`extensions.ts` widens Document to `'(block | textBox)+'`) — never in table cells, lists, header/footer, or other boxes; imports found there are flattened with a warning. `TextBoxView` mirrors `ImageView` (wrapper reserving the rotated bbox → rotor carrying fill/stroke/rotation → `contentDOM`); the rotor is out of flow and auto-grows, so a ResizeObserver refits the wrapper. **Click model (Word-like):** `stopEvent`/`isFrameHit` claim mouse events on a ~6px frame ring (rotation-/zoom-aware) → NodeSelection + handles (the shared `image-*` handle classes/CSS); clicks further inside pass to ProseMirror (caret). The box is browser-`draggable` only while node-selected, so PM's native block drag moves it without hijacking text selection. Commands: `insertTextBox()` (after the current top-level block, cursor inside), `setTextBoxAttrs()` (NodeSelection *or* cursor inside; helper `findTextBox`). `TextBoxToolbar.svelte` (wired in `Editor.svelte` like the image toolbar, also shown while the caret is inside a box) sets wrap/shape/fill/stroke. `trailingNode.ts` appends a paragraph after a trailing box; `pageBreaks.ts` paginates `.textbox-node` atomically. **Spacing:** a box lifted out of an anchor paragraph that held nothing else stands in for it, so it takes that paragraph's resolved `fo:margin-top`/`-bottom` as `spaceBefore`/`spaceAfter` (`ParagraphSpacing` covers `textBox` for that). Space above is padding — it adds to the block above rather than collapsing against it — which means the node is `content-box` and the rotor, centred in the padding box, gets half of it back.

src/lib/editor/extensions/image.ts

@@ -255,18 +255,27 @@ export const Image = Node.create({
 // against LibreOffice). Whitespace beside the image adds none, which CSS cannot ask.
 const imageLineKey = new PluginKey('imageLine');
 
+// Hard breaks are the only line boundaries visible in the model, so a frame is taken
+// as alone on its line when nothing but whitespace shares its break-delimited run —
+// the image-plus-caption idiom. A soft wrap around it can't be seen from here.
 function imageLineDecorations(doc: PMNode): DecorationSet {
   const decos: Decoration[] = [];
   doc.descendants((node, pos) => {
     if (!node.isTextblock) return true;
-    let image = false;
+    let images: number[] = [];
     let text = false;
-    node.forEach((child) => {
-      if (child.type.name === 'image') {
-        if ((child.attrs.wrap ?? 'inline') === 'inline') image = true;
-      } else if (child.isText ? child.text?.trim() : child.type.name !== 'hardBreak') text = true;
+    const flush = () => {
+      if (!text) for (const at of images) decos.push(Decoration.node(at, at + 1, { class: 'image-line' }));
+      images = [];
+      text = false;
+    };
+    node.forEach((child, offset) => {
+      if (child.type.name === 'hardBreak') flush();
+      else if (child.type.name === 'image') {
+        if ((child.attrs.wrap ?? 'inline') === 'inline') images.push(pos + 1 + offset);
+      } else if (child.isText ? child.text?.trim() : true) text = true;
     });
-    if (image && !text) decos.push(Decoration.node(pos, pos + node.nodeSize, { class: 'image-line' }));
+    flush();
     return false;
   });
   return DecorationSet.create(doc, decos);

src/styles/editor.css

@@ -279,10 +279,10 @@
   vertical-align: baseline;
   line-height: 0;
 }
-/* Alone on its line (image.ts marks the block) the frame sets the line height by itself:
-   no descent hangs below it, and every vertical-pos but `offset` is moot (probed). Beats
+/* Alone on its line (image.ts marks the frame) it sets the line height by itself: no
+   descent hangs below it, and every vertical-pos but `offset` is moot (probed). Beats
    the node view's own inline alignment, which has no other way to know. */
-.paper .tiptap .image-line .image-node:not([data-v-align='offset']) {
+.paper .tiptap .image-node.image-line:not([data-v-align='offset']) {
   vertical-align: bottom !important;
 }
 /* While selected, lift the node (and its handles) above the header/footer layer