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.

src/layers/bikeshare/failureReporting.test.mjs

@@ -60,7 +60,7 @@ test('the layer reports failure when a failed city left it with nothing', () =>
 });
 
 test('a layer with nothing to draw and nothing failed is not an error', () => {
-  const { state, methods } = makeLayer();
+  const { methods } = makeLayer();
 
   // Out of range of every city is empty, not broken.
   assert.equal(methods.getStats().error, undefined);

src/layers/launches/rendering.js

@@ -109,7 +109,7 @@ export function createRendering({
       );
     });
     if (satelliteTrack) layerState._orbitMatches++;
-    const entity = layerState._dataSource.entities.add({
+    layerState._dataSource.entities.add({
       id: `rocket-launch:${launch.id}`,
       position,
       point: {

src/layers/radio/rendering.js

@@ -259,7 +259,7 @@ export function createRendering({
     layerState._horizonScanCount += 1;
     const occluder = horizonOccluder(layerState._viewer.camera);
     let visibilityChanged = false;
-    for (const [id, record] of layerState._renderById) {
+    for (const record of layerState._renderById.values()) {
       const matches = parts.categories.stationMatchesRadioCategory(
         record.station,
         layerState._filter,

src/layers/streetLevel/lineCoverage.test.mjs

@@ -317,7 +317,7 @@ test('a rejected key stops coverage requests until the layer goes off', async ()
 
 test('a rate limit keeps the drawn tiles and asks again once the wait is over', async (t) => {
   t.mock.timers.enable({ apis: ['setTimeout', 'Date'] });
-  const { viewer, source, state, coverage } = setup();
+  const { viewer, source, coverage } = setup();
   coverage.refresh();
   source.calls[0].reject(
     Object.assign(new Error('rate limited'), { retryAfterSec: 30 }),
@@ -593,7 +593,7 @@ test('a tile that fails before the terrain table loads is reported at once, neve
 });
 
 test('the selected sequence is drawn and highlighted even past the per-tile cap', async () => {
-  const { state, source, coverage, centre, viewer } = setup();
+  const { state, source, coverage, centre } = setup();
   const line = (n) => [
     [
       [centre.lon - 0.001, centre.lat + n * 1e-6],

src/layers/transit/lifecycle.test.mjs

@@ -1406,7 +1406,6 @@ test('the selected card lands where the vehicle stopped, not short of it', async
   // segment ends left it a few metres behind, and then the render hold was
   // released with no frame scheduled to close the gap.
   const app = harness(t);
-  const start = Date.now();
   app.serve('mbta', () => ({
     status: 200,
     body: snapshot('mbta', 'MBTA', [vehicle('b', 42.36, -71.06, reported())], {

src/layers/wind/index.test.mjs

@@ -97,7 +97,7 @@ const complete = (model, extra = {}) => ({
 });
 test('local appearance and units reuse the loaded field; optional scalar requests remain separate', async () => {
   const requests = [];
-  const { layer, calls } = harness({
+  const { layer } = harness({
     getSnapshot: async (args) => {
       requests.push(args);
       return complete(