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/core/model/Asset.ts

@@ -4,7 +4,6 @@ import type { AssetType } from './AssetTypes';
 import type { PropertyBag } from './Properties';
 import type { SceneObject } from './SceneObject';
 
-/** Every asset has an id, a name, a type and a bag of typed properties (see PropertySchema). */
 export interface AssetBase {
   id: string;
   type: AssetType;
@@ -20,58 +19,38 @@ export interface CameraAsset extends AssetBase {
   type: 'camera';
 }
 
-/**
- * A line of text drawn in the scene (titles, HUD readouts, buttons). Its content is the
- * ordinary property `text`, so behaviors change it with `Set text` (or `Set property`).
- */
 export interface TextAsset extends AssetBase {
   type: 'text';
 }
 
-/** A scene is an asset that additionally owns the objects placed into it. */
 export interface SceneAsset extends AssetBase {
   type: 'scene';
   objects: SceneObject[];
 }
 
-/**
- * A behavior is logic: a node graph plus the variables it declares. Variables are ordinary
- * properties – `variables` is the asset's own property schema, `props` holds their default
- * values, and placed instances override them like any other property.
- */
+/** `variables` is this asset's own property schema; `props` holds their default values. */
 export interface BehaviorAsset extends AssetBase {
   type: 'behavior';
   variables: PropertyDef[];
   graph: Graph;
 }
 
-/**
- * A collider is a shape (box or circle) used for collision detection. Placed as a child of
- * the object it belongs to (its "body"); its position is the offset from that body.
- */
+/** Placed as a child of the object it belongs to; its position is the offset from that body. */
 export interface ColliderAsset extends AssetBase {
   type: 'collider';
 }
 
 /**
- * A container is a reusable group of objects (a "prefab"): its `objects` are a template that
- * is instantiated below the container whenever it is placed. Template positions are local
- * to the container's origin – the centre of the group when it was created from a selection.
- * Template ids are private to the asset; every placed copy gets fresh ids and remembers the
- * template object it came from (`SceneObject.templateId`).
+ * `objects` is a template instantiated below the container whenever it is placed. Template
+ * positions are local to the container's origin, and every placed copy gets fresh ids and
+ * remembers the template object it came from (`SceneObject.templateId`).
  */
 export interface ContainerAsset extends AssetBase {
   type: 'container';
   objects: SceneObject[];
 }
 
-/**
- * One named rectangle of a texture, in image pixels – a frame of a sprite sheet.
- *
- * Its `id` is drawn from the same generator as asset ids and is unique across the document,
- * which is what lets a sprite's `texture` property name either a whole texture or one frame
- * of it (see `model/texture.ts`).
- */
+/** `id` shares the generator with asset ids and is unique across the document (see `model/texture.ts`). */
 export interface TextureFrame {
   id: string;
   name: string;
@@ -82,23 +61,9 @@ export interface TextureFrame {
 }
 
 /**
- * An uploaded image. `file` names it in `data/textures/` and is content-addressed
- * (`{sha256}.{ext}`), so the same picture uploaded twice is one file and a stored file can be
- * cached forever – its name cannot ever come to mean different bytes.
- *
- * Like a scene's objects and a behavior's graph, this is intrinsic data rather than a
- * property: nothing about it is editable or overridable per instance. What *is* a property
- * is the reference to it – sprites carry `texture` (see PropertySchema), which is how
- * instance overrides, "Apply to container" and `Set property` work on it for free.
- *
- * `frames` cuts the picture into named rectangles (the Texture tab draws them); a texture
- * with no frames is simply used whole, which is what every single-image texture wants and
- * what every document written before frames existed already says.
- *
- * `width`/`height` are the pixel size as uploaded, kept so a sprite can be sized to its
- * picture without waiting for the image to load – and so frames can be validated and sliced
- * before it arrives. An empty `file` means the upload failed or has not happened yet; such a
- * texture draws as nothing.
+ * `file` names the image in `data/textures/` and is content-addressed (`{sha256}.{ext}`), so it
+ * can be cached forever; empty means the upload failed or has not happened yet. `width`/`height`
+ * are the size as uploaded, so frames can be sliced and validated before the image loads.
  */
 export interface TextureAsset extends AssetBase {
   type: 'texture';