refactor: remove WHAT-comments, keep WHY and RFC references

static/components/PaneSubObjects.js

@@ -2,14 +2,11 @@ import { h } from 'vue';
 import { ObjectShort } from './ObjectShort.js';
 import { getKindGroups } from '../subobject-kinds.js';
 
-// Strip the final maximal run of same-class characters (all-digits or all-non-digits)
-// from the ID tail. Everything before that run is the group key.
 function _barGroupKey(id) {
     const m = id.match(/(\d+|\D+)$/);
     return m ? id.slice(0, m.index) : id;
 }
 
-// Increment the trailing numeric run of an ID, preserving zero-padding width.
 function _incrementId(id) {
     const m = id.match(/(\d+)$/);
     if (!m) return id + '1';