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/store/http.ts

@@ -1,10 +1,8 @@
 /**
- * The bit of HTTP handling both stores share. It exists because a failed response does not
- * always come from our API: nginx caps request bodies at 1 MB and answers a larger one with
- * its own HTML page, so there is no `{error}` object to read the reason from.
+ * A failed response does not always come from our API: nginx caps request bodies at 1 MB and
+ * answers a larger one with its own HTML page, so there is no `{error}` object to read.
  */
 
-/** Reasons for the statuses that can arrive without an API body of their own. */
 const STATUS_MESSAGES: Record<number, string> = {
   400: 'Bad request',
   403: 'Forbidden',
@@ -16,7 +14,6 @@ const STATUS_MESSAGES: Record<number, string> = {
   504: 'Server timed out',
 };
 
-/** What to tell the user about a failed response whose body is not our JSON – the status is all there is. */
 export function statusMessage(status: number, statusText: string): string {
   return STATUS_MESSAGES[status] ?? (statusText || `HTTP ${status}`);
 }