Trim needless comments and fix the picker width

Remove comments that only restate the code, keeping the section banners
and the notes that carry a reason, a measured fact or an external
contract.

ButtonOptions.width claimed to be a fixed width but only set minWidth,
so the Graph and Texture pickers grew with the name they showed. It is
now what it promises, with a separate minWidth for the buttons that have
two forms. Narrow buttons shrink their padding, otherwise a 24px icon
button had 8px left for its glyph and truncate dropped it entirely.

__gm.labelsDropped() guards that class: the overflow guard only saw text
that was too wide, never a label truncated to nothing.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/editor/texture/SliceDialog.ts

@@ -2,18 +2,13 @@ import type { TextureAsset } from '../../core/model/Asset';
 import { DEFAULT_SLICE, type SliceOptions, sliceFrames } from '../../core/model/texture';
 import { Button, Checkbox, HStack, Label, NumberField, Popup, Spacer, Theme, type Widget } from '../../ui';
 
-/** Width of the label column, matching the inspector's so the two read as one language. */
+/** Matches the inspector's label column. */
 const LABEL_WIDTH = 76;
 const FIELD_WIDTH = 76;
 
 /**
- * Cuts a sheet into a grid. Asks for the number of columns and rows rather than a cell size:
- * everyone knows how many tiles their sheet has, and deriving the cell size from the picture
- * cannot disagree with it.
- *
- * The dialog states, live, how many frames the current numbers would produce and how big each
- * one is. That readout is the whole point – it turns "did I mean 8×4 or 4×8" from something
- * you find out by undoing into something you see before committing.
+ * Cuts a sheet into a grid, asked for as columns and rows rather than a cell size: the counts are
+ * what the user knows, and a cell size derived from the picture cannot disagree with them.
  */
 export class SliceDialog extends Popup {
   private readonly options: SliceOptions = { ...DEFAULT_SLICE };
@@ -60,7 +55,6 @@ export class SliceDialog extends Popup {
     this.refreshSummary();
   }
 
-  /** Two numeric fields on one row – the grid's parameters come in x/y pairs. */
   private pair(
     labelA: string,
     keyA: keyof SliceOptions,
@@ -90,7 +84,7 @@ export class SliceDialog extends Popup {
     const field = new NumberField(this.options[key], {
       min,
       step: 1,
-      // Counts of cells and pixel offsets; the value is rounded on change, so 0 hides nothing.
+      // Counts and pixel offsets, rounded on change, so 0 decimals hides nothing.
       decimals: 0,
       onChange: (value) => {
         this.options[key] = Math.round(Number(value));
@@ -101,7 +95,6 @@ export class SliceDialog extends Popup {
     return field;
   }
 
-  /** Live readout of what the current numbers would do, including the refusal case. */
   private refreshSummary(): void {
     const rects = sliceFrames(this.asset.width, this.asset.height, this.options);
     const first = rects[0];