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/ui/Theme.ts

@@ -1,8 +1,4 @@
-/**
- * Design tokens for the canvas UI. Widgets take every color and text style from here and
- * the sizes they share (row/control heights, spacing, the few named control sizes); sizes
- * that only one widget uses may stay local to it.
- */
+/** Design tokens for the canvas UI. Sizes only one widget uses may stay local to it. */
 import { TextStyle } from 'pixi.js';
 
 export const Theme = {
@@ -15,13 +11,9 @@ export const Theme = {
   padding: 8,
   gap: 6,
   radius: 4,
-  /** Horizontal inset of text inside text fields. */
   fieldPadding: 6,
-  /** Side length of the checkbox square (centred inside the control height). */
   checkboxSize: 16,
-  /** Side length of the small color marker in list rows. */
   swatchSize: 12,
-  /** Width of the scrollbar thumb. */
   scrollbarWidth: 6,
   /** Horizontal indent per nesting level in tree lists. */
   treeIndent: 14,
@@ -46,9 +38,7 @@ export const Theme = {
     /** Collider outlines: solid (blocking) and trigger (events only). */
     collider: 0x4fd18b,
     trigger: 0xf2c84b,
-    /** Container (group) symbols. */
     container: 0x3fb8c9,
-    /** Rubber-band selection rectangle. */
     marquee: 0x4c8dff,
     /** Node graph: canvas, node chrome, per-category title colors, port colors, live highlight. */
     graphBackground: 0x15171b,
@@ -72,7 +62,6 @@ export const Theme = {
 
 const styleCache = new Map<string, TextStyle>();
 
-/** Named text styles; every piece of text in the UI uses one of these. */
 export type TextStyleToken = 'body' | 'bodyBold' | 'muted' | 'small' | 'title' | 'mono' | 'accent';
 
 /** Shared TextStyle instances so Pixi can cache glyph measurements per token. */