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/commands/require.ts

@@ -1,8 +1,4 @@
-/**
- * Lookups that throw a `CommandError` when the target does not exist. Commands validate
- * their inputs with these before mutating anything, so an invalid edit is rejected with a
- * message the editor can show.
- */
+/** Lookups that throw a `CommandError` when the target does not exist. */
 import { findNode, type GraphNode } from '../graph/Graph';
 import { type NodeDef, nodeDef } from '../graph/NodeRegistry';
 import type { Asset, BehaviorAsset, SceneAsset } from '../model/Asset';
@@ -43,9 +39,8 @@ export function requireNode(project: Project, assetId: string, nodeId: string):
 }
 
 /**
- * The definition of a node type. `NodeRegistry.requireNodeDef` throws a plain `Error`, which
- * the editor does not catch – a command must reject an unknown type as a `CommandError` so it
- * becomes a notice instead of a crash.
+ * `NodeRegistry.requireNodeDef` throws a plain `Error`, which the editor does not catch; a command
+ * needs a `CommandError` so an unknown type becomes a notice instead of a crash.
  */
 export function requireNodeDef(type: string): NodeDef {
   const def = nodeDef(type);
@@ -53,7 +48,6 @@ export function requireNodeDef(type: string): NodeDef {
   return def;
 }
 
-/** The schema entry for `key` on the asset – a property the asset's type (or the behavior) declares. */
 export function requirePropDef(asset: Asset, key: string): PropertyDef {
   const def = propDef(asset, key);
   if (!def) throw new CommandError(`Property "${key}" is not defined for ${asset.type}`);