chore: remove the remaining unused local bindings

An ESLint no-unused-vars scan over src, server, scripts, tools, build
and pinokio, repeated until it is stable, reported these.

Runtime modules keep every call and drop only the unread binding:
- src/ui/cockpitInput.js: the unread result of enter()/exit().
- src/layers/launches/rendering.js: the unread entity returned by
  entities.add().
- src/layers/radio/rendering.js: the unread map key in the horizon scan,
  which now iterates the map's values.

QA scripts and tools drop an unused helper, two unused in-page module
imports, unused counters and destructured fields, and an unread wait
result. Tests drop source files read into variables that no assertion
uses, redundant StyleManager imports (the shell-source helper already
imports it), and unused destructured fields.

The one remaining report is the `_` loop variable in src/tools/schema.js,
which counts iterations and is intentional.

scripts/qa-final-polish-credits.mjs

@@ -52,7 +52,6 @@ try {
       id,
       value,
     );
-  const text = () => page.$eval('#cesium-credits', (e) => e.innerText);
   const shot = async (name, osm, tiles) => {
     await sleep(300);
     const state = await page.$eval('#cesium-credits', (e) => {