Split the debug hook into one file per topic (#215)

debugHook.ts had grown to 1097 lines of unrelated test hooks. They
now live in seven files under src/editor/debug/, grouped by topic.
debugHook.ts only assembles them and is down to 86 lines.

- The shape of window.__gm is unchanged for tools/. Measured in the
  browser before and after: 120 top-level keys and 313 leaves with
  their arity, byte-identical JSON.
- The Text import is explicit in the helpers. Without it the name
  fell back to the DOM type and instanceof would never have matched.

Findings:
- The comment for vectorArt sat above pixelArt. It is back in place.
- An orphaned duplicate comment on assetRow is gone.

Tests:
- ./check.sh: 145 files, 2192 tests, CHECK EXIT 0 (unchanged)
- e2e 1-16,37,39-43,47,48: ALL PASSED, 734 checks
- The shape probe turns red against a deliberately misnested hook.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/editor/debug/documentHooks.ts

@@ -0,0 +1,89 @@
+import { findAsset, findAssetOf } from '../../core/model/Project';
+import { previewObjectId } from '../../core/model/animationPreview';
+import { currentFramesDialog } from '../animation/FramesDialog';
+import { currentRowDialog } from '../animation/RowDialog';
+import { centreOf, type HookContext } from './hookHelpers';
+
+/** The Texture, Animation, Tile and List tabs. */
+export function documentHooks({ state, editor }: HookContext) {
+  const { textureEditor } = editor;
+  return {
+    texture: {
+      current: () => textureEditor.currentAssetId,
+      /** Where an image pixel of the shown sheet sits on screen (frames are dragged in image coordinates). */
+      pointAt: (x: number, y: number) => textureEditor.imageToScreen(x, y),
+      rect: () => textureEditor.canvasRect(),
+      /** Whether a press edits the selected frame's collision outline (#141). */
+      collisionMode: () => textureEditor.canvas.collisionMode,
+      /** The open "Generate collision…" dialog (#161), or null. */
+      generateDialog: () => textureEditor.generateDialog.current()?.info ?? null,
+    },
+    animation: {
+      current: () => editor.animationEditor.currentAssetId,
+      info: () => editor.animationEditor.shownInfo,
+      rootPickerAt: () => centreOf(editor.animationEditor.rootPicker),
+      addRowAt: () => centreOf(editor.animationEditor.addRowButton),
+      playAt: () => ({
+        ...centreOf(editor.animationEditor.playButton),
+        text: editor.animationEditor.playButton.text,
+      }),
+      /** Where a cell, a row's header and a frame on the ruler sit – no text names a cell. */
+      cellAt: (trackId: string, frame: number) => editor.animationEditor.canvas.cellGlobal(trackId, frame),
+      headerAt: (trackId: string) => editor.animationEditor.canvas.headerGlobal(trackId),
+      rulerAt: (frame: number) => editor.animationEditor.canvas.rulerGlobal(frame),
+      keys: () => editor.animationEditor.canvas.keysDrawn(),
+      rows: () => editor.animationEditor.canvas.rowsDrawn(),
+      view: () => editor.animationEditor.canvas.viewInfo(),
+      scrub: (frame: number) => editor.animationEditor.canvas.scrub(frame),
+      /** The open row dialog: what it offers and holds, and a way to pick without clicking through menus. */
+      rowDialog: () => currentRowDialog()?.debugInfo() ?? null,
+      rowDialogPick: (target: string, property: string) => currentRowDialog()?.pick(target, property),
+      /** Copy/paste and frames (#102): what the clipboard holds, and the open frames dialog. */
+      clipboard: () => structuredClone(state.keyClipboard),
+      framesDialog: () => currentFramesDialog()?.debugInfo() ?? null,
+      framesDialogCount: (count: number) => currentFramesDialog()?.setCount(count),
+      framesDialogConfirm: () => {
+        const dialog = currentFramesDialog();
+        if (!dialog) return null;
+        const g = dialog.confirm.getGlobalPosition();
+        return { x: g.x + dialog.confirm.w / 2, y: g.y + dialog.confirm.h / 2 };
+      },
+      /** The preview above the timeline (#99): where a row's target is drawn and with which values. */
+      preview: {
+        /** The id the preview draws a row's target under (`''` = the root itself). */
+        objectId: (target: string) => {
+          const asset = findAssetOf(state.project, editor.animationEditor.currentAssetId, 'animation');
+          return previewObjectId(asset && findAsset(state.project, asset.root), target);
+        },
+        rect: (objectId: string) => editor.animationEditor.preview.objectRect(objectId),
+        item: (objectId: string) => editor.animationEditor.preview.itemDrawn(objectId),
+        info: () => editor.animationEditor.preview.debugInfo(),
+        fitAt: () => centreOf(editor.animationEditor.fitButton),
+      },
+    },
+    tile: {
+      current: () => editor.tileEditor.currentAssetId,
+      info: () => editor.tileEditor.shownInfo,
+      /** What the board drew: tiles, the picture it is showing and what stands in the way. */
+      board: () => editor.tileEditor.canvas.debugInfo(),
+      pictures: () => editor.tileEditor.strip.debugInfo(),
+      /** A tile of the board: its quarters and where each of them is drawn. */
+      tile: (index: number) => editor.tileEditor.canvas.tileDrawn(index),
+      /** Which board tile a cell of the sample map became – `-1` when that cell is empty. */
+      sampleTile: (row: number, column: number) => editor.tileEditor.canvas.sampleTile(row, column),
+      kindPickerAt: () => centreOf(editor.tileEditor.kindPicker),
+      addPictureAt: () => centreOf(editor.tileEditor.strip.addButton),
+      removePictureAt: () => centreOf(editor.tileEditor.strip.removeButton),
+      pictureRowAt: (index: number) => editor.tileEditor.strip.list.rowGlobal(String(index)),
+      fitAt: () => centreOf(editor.tileEditor.fitButton),
+    },
+    list: {
+      info: () => editor.listEditor.debugInfo(),
+      /** Where an item's widget sits, so a check can click it – a number field has no findable text. */
+      fieldAt: (index: number, field = '') => editor.listEditor.fieldAt(index, field),
+      /** The kind mark of a row, or of one field of a struct item – both are pickers. */
+      markAt: (index: number, field = '') => editor.listEditor.markAt(index, field),
+      nameAt: (index: number, field: string) => editor.listEditor.nameAt(index, field),
+    },
+  };
+}