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/container.ts

@@ -4,7 +4,6 @@ import { chainOf, type ObjectTree } from './hierarchy';
 import { findAsset, objectsWhere, type Project, type SceneObjectRef } from './Project';
 import type { SceneObject } from './SceneObject';
 
-/** What a placed container's content object is linked to: the container and its template object. */
 export interface TemplateLink {
   containerObject: SceneObject;
   asset: ContainerAsset;
@@ -12,9 +11,8 @@ export interface TemplateLink {
 }
 
 /**
- * For an object that belongs to a placed container: the nearest container ancestor whose
- * asset holds the template this object was instantiated from. Undefined for everything else
- * (no template id, or the link is stale).
+ * The nearest container ancestor whose asset holds the template `object` was instantiated from;
+ * undefined when it has no template id or the link is stale.
  */
 export function templateLinkOf(
   project: Project,
@@ -32,23 +30,19 @@ export function templateLinkOf(
 }
 
 /**
- * Every placed copy of a template object (template ids are unique per project). Template
- * objects themselves never carry a template id, so a template is never mistaken for a copy
- * of itself even though the search covers container assets too.
+ * Every placed copy of a template object. Template objects themselves never carry a template id, so
+ * one is never mistaken for a copy of itself even though the search covers container assets too.
  */
 export function instancesOf(project: Project, templateId: string): SceneObjectRef[] {
   return objectsWhere(project, (o) => o.templateId === templateId);
 }
 
-/** Nesting depth at which a container inside a container inside … stops being expanded. */
 const MAX_NESTING = 8;
 
 /**
- * The scene objects a placed container consists of: one fresh object per template object,
- * parented below `containerObjectId` (or below the copy of their template parent), each
- * remembering its template id. A template object that is itself a container is expanded in
- * turn – unless the template already spells its content out (that is what a container built
- * from a selection containing another container does).
+ * One fresh object per template object, parented below `containerObjectId` or below the copy of its
+ * template parent. A template object that is itself a container is expanded in turn, unless the
+ * template already spells its content out.
  */
 export function instantiateContainer(
   project: Project,
@@ -68,8 +62,7 @@ export function instantiateContainer(
       assetId: template.assetId,
       name: template.name,
       position: { ...template.position },
-      // The editor offset stays with the instance, never with the template: it is a view tweak
-      // on one placed object, not something every copy of the container should inherit.
+      // The editor offset is a tweak on one placed object, not something copies should inherit.
       editorOffset: { x: 0, y: 0 },
       overrides: { ...template.overrides },
       parentId,