chore: drop exports nothing imports

Knip, configured with the application, package exports, scripts, QA
harnesses, workers, tools and tests as entry points, reports exports
that no module imports. Each was checked by hand against string-based
and namespace imports.

- Symbols that are still used inside their own module lose only the
  `export` keyword (176 constants and helpers).
- Unused re-exports are removed from barrel modules (flight, military,
  vessel, CCTV, directions, transit history, local ADS-B and street-level
  policy modules).
- Declarations that nothing uses at all are deleted, among them
  AIS_WATCHDOG_STATUSES, applyFilter, isRadioCountryCode, compactText,
  DENSITY_STOPS, the unused CCTV endpoint constants, and the SDR band
  constants.
- Default exports that nothing imports are removed. The ones in
  src/data/earthquakes.js, src/data/telegeographySubmarineCables.js,
  src/data/wind.js and src/data/bhoteKoshiLocator.js each constructed a
  layer instance at import time that nothing used; those instances are
  no longer created.

Every export of a package.json entry stays, as does TOMTOM_CREDIT,
which the traffic layer reads from the credits namespace it is given.

src/layers/streetLevel/photoViewer.js

@@ -17,18 +17,18 @@ const EXPANDED_SELECTORS = [
 ];
 
 /** A photo download (tens of kilobytes to a few megabytes). */
-export const IMAGE_TIMEOUT_MS = 15_000;
+const IMAGE_TIMEOUT_MS = 15_000;
 
 /** A picture file or decoded side past these is refused (a photo is a few MB). */
 export const MAX_IMAGE_BYTES = 48 * 1024 * 1024;
 export const MAX_IMAGE_SIDE = 16_384;
 /** 64 MP: 256 MB once decoded to RGBA. A 16,384 px square is four times that. */
-export const MAX_IMAGE_PIXELS = 8_192 * 8_192;
+const MAX_IMAGE_PIXELS = 8_192 * 8_192;
 /** Where in a file to look for its dimensions (a JPEG's EXIF comes first). */
 const HEADER_BYTES = 256 * 1024;
 
 /** Whether a picture this size is past what the viewer decodes. */
-export function tooManyPixels(width, height) {
+function tooManyPixels(width, height) {
   return (
     width > MAX_IMAGE_SIDE ||
     height > MAX_IMAGE_SIDE ||
@@ -37,7 +37,7 @@ export function tooManyPixels(width, height) {
 }
 
 /** Panorama texture widths: enough for a docked viewer, and for an expanded one. */
-export const PANO_MID_SIZE = Object.freeze([2048, 1024]);
+const PANO_MID_SIZE = Object.freeze([2048, 1024]);
 export const PANO_FULL_SIZE = Object.freeze([4096, 2048]);
 
 /**
@@ -155,7 +155,7 @@ async function loadBitmap(url, timeoutMs, resize, failure, signal) {
  * A picture refused for its size (`tooLarge`): the viewer will not load
  * that file another way, an <img> having no size limit at all.
  */
-export function oversized(failure) {
+function oversized(failure) {
   return Object.assign(new Error(failure), { tooLarge: true });
 }
 

src/layers/streetLevel/providers/kartaview/policy.js

@@ -14,7 +14,7 @@ export const KARTAVIEW_LABEL = 'KARTAVIEW';
  */
 export const KARTAVIEW_API_HOST = 'https://api.kartaview.org';
 /** KartaView's image proxy: resizes a photo given its base64url address. */
-export const KARTAVIEW_CDN_HOST = 'https://cdn.kartaview.org';
+const KARTAVIEW_CDN_HOST = 'https://cdn.kartaview.org';
 
 /** Stable id prefixes for picked primitives; every one starts with `kv:`. */
 export const PICK_PREFIX = Object.freeze({
@@ -140,8 +140,6 @@ export const MASK_SLOW_MESSAGE = msg(
 export const FILTERED_OUT_MESSAGE = msg(
   'None of KartaView’s photos here pass the imagery filter',
 );
-/** Under the SINCE slider while KartaView is lit. */
-export const SINCE_NOTE = '(by upload date)';
 
 /** The UTC calendar day of `ms`, as KartaView's startDate reads it. */
 function utcDay(ms) {

src/layers/streetLevel/providers/panoramax/index.js

@@ -41,8 +41,6 @@ import {
   normalizeItem,
 } from './policy.js';
 
-export { PANORAMAX_PROVIDER_ID } from './policy.js';
-
 /**
  * A tile's bytes decoded by `decode`; a body that is not a vector tile
  * (an HTML error page, a cut-off answer) reads as such, not as a parser's

src/layers/streetLevel/providers/panoramax/policy.js

@@ -15,7 +15,7 @@ export const PANORAMAX_LABEL = 'PANORAMAX';
  */
 export const PANORAMAX_API = 'https://api.panoramax.xyz/api';
 /** The meta-catalogue's web viewer, where the caption link goes. */
-export const PANORAMAX_VIEWER = 'https://api.panoramax.xyz/';
+const PANORAMAX_VIEWER = 'https://api.panoramax.xyz/';
 
 /** Stable id prefixes for picked primitives; every one starts with `pnx:`. */
 export const PICK_PREFIX = Object.freeze({

src/layers/streetLevel/registry.js

@@ -1,6 +1,6 @@
 import { encodeIdSwitches } from '../../data/idSwitches.js';
 
-export const IMAGERY_FILTERS = Object.freeze(['pano', 'since']);
+const IMAGERY_FILTERS = Object.freeze(['pano', 'since']);
 
 export function filtersOf(provider) {
   return provider?.filters ?? IMAGERY_FILTERS;

src/layers/streetLevel/sequenceCones.js

@@ -5,8 +5,8 @@ import { createHorizonCull, metresBetween } from './view.js';
 import { msg } from '../../i18n/index.js';
 
 /** Cones closer than this to the previous kept one are dropped. */
-export const IMAGE_CONE_MIN_SPACING_M = 3;
-export const IMAGE_CONE_SIZE_PX = 26;
+const IMAGE_CONE_MIN_SPACING_M = 3;
+const IMAGE_CONE_SIZE_PX = 26;
 
 /**
  * @typedef {object} ConeImage   One image of a sequence, as the cones draw it.

src/layers/streetLevel/tileCache.js

@@ -1,6 +1,6 @@
 /** Decoded coverage tiles kept, and for how long. */
-export const TILE_CACHE_SIZE = 24;
-export const TILE_CACHE_TTL_MS = 10 * 60_000;
+const TILE_CACHE_SIZE = 24;
+const TILE_CACHE_TTL_MS = 10 * 60_000;
 
 /** Least-recently-used map: reading an entry renews it. */
 export function createLru(limit) {

src/layers/streetLevel/uiState.js

@@ -64,7 +64,7 @@ export function keyAlternatives(providers) {
  * The filter controls a switched-on provider honours (both when none is on).
  * @param {Array<ProviderSnapshot>} providers
  */
-export function filterControls(providers) {
+function filterControls(providers) {
   const active = providers.filter((p) => p.on);
   const honoured = (key) =>
     active.length === 0 ||
@@ -78,7 +78,7 @@ export function filterControls(providers) {
  * note needs no provider name.
  * @param {Array<ProviderSnapshot>} providers
  */
-export function sinceNote(providers) {
+function sinceNote(providers) {
   return providers.some((p) => p.on && p.sinceBasis === 'upload')
     ? t('(by upload date)')
     : null;