Editor: interactive composition wireframe — drag to reorder and restructure

Drag a view's box (or Alt+up/down) to reorder it within its container; drag onto another view's edge to pair the two in a new row/column, move across containers, or insert. Each leaf shows a glyph of its mark type.

Core: spec-restructure.wrapViews (wrap, with flatten-to-insert, collapse, and data-pin invariants) and spec-insert.moveViewTo; the editor applies every drag as one undoable edit via AppStore.composeRequest, keeping the editor the single text source.

docs/architecture/08-vega-editor-techniques.md

@@ -297,13 +297,24 @@ thin app-layer services.
 - `spec-inline-data` — the rows a specific `data` binding carries for profiling
   (`rowsForDataBinding`: inline `values`, or a self-defined `datasets` entry).
 - `spec-insert` — the composition the cursor is in (`compositionTargetAt`), inserting a view
-  at an index (`insertView`) and reordering siblings (`moveView`), plus `elementOffset` to
-  re-find a view after the edit.
+  at an index (`insertView`) and reordering siblings (`moveView` swaps a neighbour, `moveViewTo`
+  slides to any index), plus `elementOffset` to re-find a view after the edit. It also owns the
+  shared `SpecPath` walkers (`valueAtPath`/`arrayAtPath`/`isPrefixPath`) — a module navigating a
+  path reuses these rather than re-inlining the array/object descent.
 - `spec-view-tree` — the whole composition as a recursive tree (`viewTree`), each node carrying
   its operator, orientation and byte range. Read at once (vs. `spec-insert`'s one-array edits) to
-  drive the composition wireframe — a read-only schematic of the multi-view structure in a preview-
-  toolbar disclosure (`CompositionWireframe`); clicking a box reveals that view's range in the
-  editor via `AppStore.requestRevealView`. Interaction contract in [arch 10](10-interaction-and-feedback.md).
+  drive the composition wireframe — a schematic of the multi-view structure in a preview-toolbar
+  disclosure (`CompositionWireframe`); clicking a box reveals that view's range in the editor via
+  `AppStore.requestRevealView`, and on the draft it is **drag-editable** (reorder + restructure).
+  Interaction contract in [arch 10](10-interaction-and-feedback.md).
+- `spec-restructure` — the path-targeted cross-container moves behind the wireframe's drag.
+  `wrapViews(target, source, axis, side)` pairs the dragged source beside the drop target in a new
+  concat (placed where the target was, the source removed), enforcing three invariants:
+  **flatten** a bare same-orientation concat nested directly in a concat (so a with-axis drop reads
+  as a plain _insert_, not redundant nesting), **collapse** the source's emptied container (unwrap a
+  one-child, drop a zero-child, recursing up the chain), and **data-pin** a source's inherited
+  `data` before it changes ancestor (`dataBindingAtPath`, so it never silently rebinds). Degenerate
+  drops — onto itself, its own ancestor/descendant, or the root — return null.
 
 **Services (app, store-aware via `getState`):** `spec-transform-actions` (the
 wrap/simplify/add-view operations and their surfaces), `spec-dataset-hints` (completion,
@@ -325,6 +336,13 @@ Decision rules:
 - **One edit path.** The lightbulb returns a `WorkspaceEdit` (no editor handle); the toolbar
   and palette use `executeEdits`. Both build the replacement through the same
   serialize-and-reindent step, bracketed by `pushUndoStop`, so ⌘Z restores the prior text.
+- **Wireframe restructuring is one core op + the editor's undo.** Every drag resolves to either
+  `moveViewTo` (reorder within one container) or `wrapViews` (everything else — wrap, cross-container
+  move, insert); the wireframe only _requests_ it (`AppStore.requestComposeMove`/`requestComposeWrap`)
+  and `SpecEditor` applies it through the same `executeEdits` + `pushUndoStop` path as the other
+  transforms, so a drag is one ⌘Z and the editor stays the single text source. `wrapViews` covers
+  wrap and insert with one operation because it flattens bare same-orientation nesting afterward; the
+  drag's edge-zone interaction model lives in [arch 10](10-interaction-and-feedback.md).
 - **Composition CodeLens is cursor-scoped.** It follows the view the cursor sits in —
   `＋ Add view above/below` at the view's edges and `↑/↓ Move` to reorder among its siblings —
   rather than one fixed button per composition array; an empty composition shows a single `＋ Add view`,

docs/architecture/09-visual-design.md

@@ -371,6 +371,14 @@ notifications/validation as they arrive):
 | Success | `CheckmarkFilled`    | `--support-success`     | `Toaster` (success)                         |
 | Info    | `InformationFilled`  | `--support-info`        | `Toaster` (info)                            |
 
+**Mark set** — a custom `mark-*` sub-family, one simplified glyph per Vega-Lite mark
+(bar, line, area, point, arc, rect, tick, rule, text, plus a `mark-generic` fallback),
+drawn on the same 32-grid (stroked where a line reads truer than a fill). It labels the
+leaves of the composition wireframe so views read apart at a glance; mark synonyms
+(circle/square → point, trail → line, image → rect) collapse onto it via `markIconName`
+(`mark-icon.ts`), and an unknown or absent mark falls to `mark-generic`. Decorative there
+(the box's `aria-label` names the view), so these are not in the ⭐ icon-only set.
+
 **Scoped set** — single-surface, glyph **reserved** in the ledger but **not yet in
 the `Icon` registry**:
 

docs/architecture/10-interaction-and-feedback.md

@@ -222,17 +222,38 @@ _(Consulted via `/council` → WAI-ARIA APG `windowsplitter`. This bullet is the
 cite it, not the APG file.)_
 
 **Resolved — composition structure wireframe.** The preview toolbar's structure disclosure (a
-read-only schematic of the spec's multi-view composition — `CompositionWireframe`, arch 08) is a
+schematic of the spec's multi-view composition — `CompositionWireframe`, arch 08) is a
 **WAI-ARIA APG `tree`** inside a disclosure popover (`usePopover`): bare nested boxes are
 `tree` → `treeitem` → `group`, single-select via `aria-selected`, **one tab stop with a roving
 tabindex**, arrow keys in **logical (document) order** — Up/Down between nodes, Left → parent,
 Right → first child, Home/End, Enter/Space activate — not spatial, since a mixed horizontal/
-vertical layout makes spatial arrows ambiguous. Selecting a box reveals + selects that view's
-source range in the editor (`AppStore.requestRevealView`) but **does not steal focus**, so the
-wireframe stays the active surface while the editor scrolls to follow; the editor selection is the
-single source of truth. The toolbar glyph appears **only for a composed spec** — a single-view
-spec hides the affordance rather than disclosing an empty tree. _(Council: APG treeview; the
-cursor-scoping reachability rationale is in [arch 08](08-vega-editor-techniques.md).)_
+vertical layout makes spatial arrows ambiguous. Each leaf carries a glyph of its mark type (the
+`mark-*` icon sub-family, arch 09 §5) so views read apart at a glance. Selecting a box reveals +
+selects that view's source range in the editor (`AppStore.requestRevealView`) but **does not steal
+focus**, so the wireframe stays the active surface while the editor scrolls to follow; the editor
+selection is the single source of truth. The toolbar glyph appears **only for a composed spec** —
+a single-view spec hides the affordance rather than disclosing an empty tree. _(Council: APG
+treeview; the cursor-scoping reachability rationale is in [arch 08](08-vega-editor-techniques.md).)_
+
+On the **editable draft** the tree restructures the composition. Every restructure is **applied by
+the editor** (which owns the one-⌘Z edit) via `AppStore.requestComposeMove`/`requestComposeWrap`,
+never by writing the draft text directly — so the wireframe and editor share one undo history.
+
+- **Reorder within a container — APG rearrangeable-listbox.** `Alt+↑`/`Alt+↓` moves the focused
+  view among its siblings: a direct modifier+arrow move, **not** a grab/drop mode. Focus follows
+  the moved box for consecutive moves (so a screen reader re-announces its new position), a
+  **polite** live region states the result, and `aria-keyshortcuts` advertises the keys. _(Council:
+  APG listbox-rearrangeable.)_
+- **Restructure by drag — edge-zone (dock) model.** The nearest edge of the box under the pointer
+  picks the **axis** (left/right → a row `hconcat`, top/bottom → a column `vconcat`) and **side**.
+  A drop **along** a sibling's own container reorders within it; a drop **across** it — or onto an
+  opaque `layer`/`facet`/`repeat` box — pairs the two in a new concat. The hit-test descends only
+  through `hconcat`/`vconcat` and treats `layer`/`facet`/`repeat`/grid as **opaque** targets (their
+  children overlap or are data-generated, so the unit is the target, never inside it). A 3px accent
+  line marks the landing edge; a `wrap` drop also rings + tints the partner box. The drag is a
+  pointer accelerator over capabilities that stay keyboard-reachable (in-container reorder via
+  `Alt+↑/↓`; cross-container wrap via the editor's wrap actions), so it adds **no keyboard-only
+  gap**. Transform invariants in [arch 08](08-vega-editor-techniques.md).
 
 **Resolved — pane toggle strip.** The persistent show/hide strip (spec §01A) is a **WAI-ARIA
 APG `toolbar`** (`role="toolbar"`, `aria-orientation="vertical"`, an `aria-label` such as