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-radio.mjs

@@ -1291,8 +1291,6 @@ async function main() {
     const clusterBadge = await page.evaluate(async () => {
       const viewer = window.__godsEyeView.viewer;
       const { getOverlayPaintRect, getWorldOverlayDiagnostics } = await import('/src/overlays/worldOverlay.js');
-      const { distanceFade } = await import('/src/overlays/worldOverlayDraw.js');
-      const { radioStationIdFromPick } = await import('/src/data/radio.js');
       const baselineSolveRevision = getWorldOverlayDiagnostics().solveRevision;
       const source = Array.from({ length: viewer.dataSources.length }, (_, index) => viewer.dataSources.get(index))
         .find((item) => item.name === 'Radio stations');