Merge origin/i18n-spanish: whole-interface translation meets KartaView

This branch moved twice at once: upstream merged KartaView (#1121, a
third keyless street-level provider sharing a new lineCoverage.js), and
the remote i18n-spanish gained the whole-interface translation work
(1993 catalog entries, translateKnown, data-i18n-runtime, the unmarked-
string detector in npm run i18n) built on the Street View merge.

Integration keeps the remote's mechanisms and re-adds KartaView on top:

- presentMeta: remote's translateHint for coverage hints, plus the
  KartaView count line as its own literal tn pair (Russian plurals need
  the noun inside the template; keyed off coverageLabel.noun with the
  sequences pair as the default).
- uiState: upstream's highlightsSequence legend gate (KartaView's lines
  do not highlight) with t('Selected').
- layer-panels.html: remote's data-i18n/data-i18n-runtime hooks plus the
  sl-since-note wiring KartaView's upload-date SINCE note needs.
- kartaview viewer: the photo-navigation aria-label and img alt go
  through t(), as the remote's unmarked-string detector requires.
- catalogs: remote's 1987-entry base (its refined keys supersede this
  branch's earlier Street View wording) plus the KartaView entries:
  coverage hints, the upload-date note, the streets count line (with
  Russian one/few/many/other forms) and the viewer strings.

npm run i18n: complete, no unmarked strings. npm test: 6520/6522 (the
one failure is the pre-existing environmental OPENAI_API_KEY leak in
devFreshDotenv). Build passes.

src/i18n/catalog.test.mjs

@@ -4,8 +4,11 @@ import assert from 'node:assert/strict';
 import {
   checkCatalog,
   extractMessages,
+  findUnmarked,
   readCatalog,
   shippedLocales,
+  unmarkedMarkup,
+  unmarkedScript,
 } from '../../scripts/i18n.mjs';
 import { LOCALES } from './locale.js';
 
@@ -32,6 +35,13 @@ for (const locale of shippedLocales()) {
   });
 }
 
+test('every UI string is marked for translation or kept on purpose (npm run i18n)', () => {
+  assert.deepEqual(
+    findUnmarked().map(({ where, text }) => `${where}  ${text}`),
+    [],
+  );
+});
+
 test('checkCatalog reports missing, stale, placeholder and plural problems', () => {
   const fixture = new Map([
     ['Saved {name}', { plural: false }],
@@ -55,3 +65,74 @@ test('checkCatalog reports missing, stale, placeholder and plural problems', ()
   assert.deepEqual(result.stale, ['Removed']);
   assert.equal(result.errors.length, 2);
 });
+
+test('checkCatalog reports a translation left in English unless it is allowed', () => {
+  const fixture = new Map([
+    ['Bloom', { plural: false }],
+    ['HDG', { plural: false }],
+    ['voice|READY', { plural: false }],
+    ['{state} · {source}', { plural: false }],
+  ]);
+  const catalog = {
+    Bloom: 'Bloom',
+    HDG: 'HDG',
+    'voice|READY': 'READY',
+    '{state} · {source}': '{state} · {source}',
+  };
+  const errors = (allowed) =>
+    checkCatalog('es', catalog, fixture, new Set(allowed)).errors;
+  assert.deepEqual(
+    errors([]).map((error) => error.split(' is still English')[0]),
+    ['"Bloom"', '"HDG"', '"voice|READY"'],
+  );
+  assert.deepEqual(errors(['Bloom', 'HDG', 'voice|READY']), []);
+});
+
+test('unmarkedMarkup finds text and attributes without data-i18n*', () => {
+  const texts = (html) => unmarkedMarkup('f.html', html).map((f) => f.text);
+  assert.deepEqual(texts('<span>Close</span>'), ['Close']);
+  assert.deepEqual(texts('<span data-i18n>Close</span>'), []);
+  assert.deepEqual(texts('<button title="Pin it">x</button>'), [
+    'title="Pin it"',
+  ]);
+  assert.deepEqual(
+    texts('<button title="Pin it" data-i18n-title>x</button>'),
+    [],
+  );
+  assert.deepEqual(
+    texts('<select translate="no"><option>0.9 dB</option></select>'),
+    [],
+  );
+  assert.deepEqual(texts('<b data-i18n-runtime><i>OFF</i></b>'), []);
+  assert.deepEqual(
+    texts('<span class="material-symbols-outlined">public</span>'),
+    [],
+  );
+  assert.deepEqual(texts('<!-- Note --><span>— 42 —</span>'), []);
+});
+
+test('unmarkedScript finds literals that reach the page without t/tn/msg', () => {
+  const texts = (js) => unmarkedScript('f.js', js).map((f) => f.text);
+  assert.deepEqual(texts("el.textContent = 'Saved';"), ['Saved']);
+  assert.deepEqual(texts("el.textContent = t('Saved');"), []);
+  assert.deepEqual(texts("el.textContent = on ? 'On air' : 'Off air';"), [
+    'On air',
+    'Off air',
+  ]);
+  assert.deepEqual(texts("el.setAttribute('aria-label', `Open ${name}`);"), [
+    'Open',
+  ]);
+  assert.deepEqual(
+    texts("const row = { label: msg('Wind'), id: 'wind' };"),
+    [],
+  );
+  assert.deepEqual(texts("const row = { label: 'Wind' };"), ['Wind']);
+  assert.deepEqual(texts("el.textContent = labelFor('flights');"), []);
+  assert.deepEqual(texts("el.className = 'is-active';"), []);
+  assert.deepEqual(texts("el.title = mode === 'Auto mode' ? a : b;"), []);
+  assert.deepEqual(texts("// el.textContent = 'Old copy';"), []);
+  assert.deepEqual(
+    texts("// i18n-ignore: product name\nel.textContent = 'OpenSky';"),
+    [],
+  );
+});

src/i18n/i18n.test.mjs

@@ -130,6 +130,12 @@ test('tn() picks English and Russian plural forms', () => {
   assert.match(label(21), / 21 КЛЮЧ(?![А-ЯЁ])/);
 });
 
+test('t() context separates identical English with different meanings', () => {
+  assert.equal(t('CLEAR', { context: 'action' }), 'CLEAR');
+  setLocale('ru');
+  assert.notEqual(t('CLEAR', { context: 'action' }), t('CLEAR'));
+});
+
 test('msg() returns its text unchanged', () => {
   assert.equal(msg('Live Flights'), 'Live Flights');
 });
@@ -182,6 +188,31 @@ test('applyDocumentTranslations translates opted-in text and attributes in place
   assert.equal(unknown.textContent, 'No such message');
 });
 
+test('persistLocaleAndReload keeps the choice in ?lang when storage is blocked', () => {
+  const calls = [];
+  const location = {
+    href: 'https://gev.local/?x=1#scene=a',
+    assign: (url) => calls.push(['assign', url]),
+    reload: () => calls.push(['reload']),
+  };
+  const history = {
+    replaceState: (_s, _t, url) => calls.push(['replace', url]),
+  };
+  const storage = {
+    setItem() {
+      throw new Error('blocked');
+    },
+  };
+  assert.equal(
+    persistLocaleAndReload('ru', { location, history, storage }),
+    true,
+  );
+  assert.deepEqual(calls, [
+    ['replace', 'https://gev.local/?x=1&lang=ru#scene=a'],
+    ['reload'],
+  ]);
+});
+
 test('persistLocaleAndReload stores the choice, keeps the hash, strips ?lang', () => {
   const storage = memoryStorage();
   const calls = [];

src/i18n/index.js

@@ -3,6 +3,7 @@
 //   t('Save keys')                                   → 'Сохранить ключи'
 //   t('Cleared {name}', { name })                    → named interpolation
 //   tn(count, '{count} camera', '{count} cameras')   → plural by Intl.PluralRules
+//   t('CLEAR', { context: 'action' })                → same English, own entry
 //   msg('Live Flights')                              → marks a string kept in data
 //                                                      for a later t(); returns it as is
 //
@@ -76,11 +77,13 @@ function lookup(text) {
 /**
  * Translate English source text into the active locale.
  * @param {string} text English text, e.g. 'Hold Space to talk'
- * @param {object} [values] Named interpolation values
+ * @param {object} [values] Named interpolation values. `context` tells
+ *   apart identical English with different meanings: t('CLEAR', { context:
+ *   'action' }) is the catalog entry "action|CLEAR"; English is unchanged.
  * @returns {string}
  */
 export function t(text, values) {
-  const entry = lookup(text);
+  const entry = lookup(values?.context ? `${values.context}|${text}` : text);
   return interpolate(typeof entry === 'string' ? entry : text, values);
 }
 
@@ -106,6 +109,18 @@ export function tn(count, one, other, values) {
   return interpolate(pattern, { ...values, count });
 }
 
+/**
+ * Translate text that may be ours or may come from a provider: a catalog
+ * entry is used when there is one, anything else shows as given, without a
+ * missing-translation warning.
+ */
+export function translateKnown(text) {
+  const catalog = CATALOGS[currentLocale];
+  if (!catalog || typeof text !== 'string') return text;
+  const entry = catalog[text];
+  return typeof entry === 'string' ? entry : text;
+}
+
 /** Mark English text that is stored in data and translated later by t(). */
 export function msg(text) {
   return text;
@@ -149,6 +164,32 @@ export function formatDate(value, options) {
   return cachedFormatter('date', Intl.DateTimeFormat, options).format(value);
 }
 
+const UTC_DAY_MONTH = Object.freeze({
+  day: '2-digit',
+  month: '2-digit',
+  timeZone: 'UTC',
+});
+
+/**
+ * The UTC day and month of a time, for "MM-DD HH:MM UTC" readouts: "10-13" in
+ * English (as before), "13.10" in Russian, "13/10" in Spanish, never read as a
+ * range. Takes an ISO string (its date part is used as written) or a time.
+ * @param {string|number|Date} value
+ * @returns {string} '' when the value is not a time.
+ */
+export function formatUtcDayMonth(value) {
+  const written =
+    typeof value === 'string' ? /^(\d{4})-(\d{2})-(\d{2})/.exec(value) : null;
+  const time = written
+    ? Date.UTC(Number(written[1]), Number(written[2]) - 1, Number(written[3]))
+    : new Date(value).getTime();
+  if (!Number.isFinite(time)) return '';
+  if (currentLocale === 'en') return new Date(time).toISOString().slice(5, 10);
+  return cachedFormatter('date', Intl.DateTimeFormat, UTC_DAY_MONTH).format(
+    time,
+  );
+}
+
 /**
  * Locale-aware relative time (Intl.RelativeTimeFormat), e.g.
  * formatRelativeTime(-5, 'minute') → '5 minutes ago' / '5 минут назад'.
@@ -209,7 +250,7 @@ export function applyDocumentTranslations(doc) {
 /**
  * Persist a locale choice, then reload preserving window.location.hash exactly
  * and stripping ?lang from the search string, so the override is one-shot.
- * Storage is best-effort: where it is blocked the choice will not survive.
+ * Where storage is blocked, ?lang carries the choice instead.
  * @returns {boolean} true when a reload was triggered.
  */
 export function persistLocaleAndReload(
@@ -221,12 +262,14 @@ export function persistLocaleAndReload(
   } = {},
 ) {
   const normalized = normalizeLocale(locale) || DEFAULT_LOCALE;
-  writeStoredLocale(normalized, storage);
+  const stored = writeStoredLocale(normalized, storage);
   if (!location || typeof location.assign !== 'function') return false;
   let target = location.href;
   try {
+    // Without storage the choice only survives in the URL, so keep it there.
     const url = new URL(location.href);
-    url.searchParams.delete('lang');
+    if (stored) url.searchParams.delete('lang');
+    else url.searchParams.set('lang', normalized);
     target = url.href;
   } catch {
     // Keep the current href.

src/i18n/same-as-english.json

@@ -0,0 +1,129 @@
+{
+  "es": [
+    "AIS: --",
+    "AIS: {name}",
+    "ANIME",
+    "ASIA",
+    "AUTO",
+    "Ambient",
+    "Anime",
+    "BRG {value}°",
+    "BRG —",
+    "Blues",
+    "CAL {value}",
+    "CAL · {badge}",
+    "CCTV",
+    "CRS {value}°",
+    "CRT",
+    "Country",
+    "DEST ---°",
+    "DEST {bearing}",
+    "Dance",
+    "ENE",
+    "ERROR",
+    "ESE",
+    "Error: {message}",
+    "FLIR",
+    "FLT",
+    "FM MHZ",
+    "FOV",
+    "FOV {value}°",
+    "FT",
+    "Folk",
+    "Funk",
+    "GEO",
+    "GOOGLE STREET VIEW",
+    "Global",
+    "Global · 60°S–60°N",
+    "Google Street View",
+    "HDG",
+    "HDG {value}°",
+    "Hip-Hop",
+    "House",
+    "Indie",
+    "Ironbow",
+    "Jazz",
+    "LOCAL",
+    "Landsat 8/9",
+    "MIC",
+    "MIL",
+    "MINI",
+    "MM",
+    "MONITOR",
+    "MSG/S",
+    "Metal",
+    "NAV",
+    "NE",
+    "NNE",
+    "NOIR",
+    "NORMAL",
+    "NVG",
+    "Noir",
+    "Normal",
+    "POS: {time}Z",
+    "Plan",
+    "Pop",
+    "Punk",
+    "R&B",
+    "RADIO",
+    "RANGE",
+    "REC",
+    "Radio",
+    "Reggae",
+    "Rock",
+    "SAR",
+    "SE",
+    "SECTOR {lat} {lon}",
+    "SIG",
+    "SRC {value}",
+    "SSE",
+    "STD",
+    "Sector",
+    "Sonar",
+    "Soul",
+    "Techno",
+    "Trance",
+    "VISUAL",
+    "VS",
+    "WHOT/BHOT",
+    "WX",
+    "audio {state}",
+    "dB",
+    "fire confidence|nominal",
+    "ft",
+    "hPa",
+    "installation class|BASE",
+    "km",
+    "km/h",
+    "min",
+    "mini",
+    "mph",
+    "nominal",
+    "panel",
+    "view band|GLOBAL",
+    "voice|ERROR",
+    "{type}  SPD: {speed}  HDG: {heading}",
+    "{value} KM",
+    "{value} KM/H",
+    "{value} KM/S",
+    "ΔE",
+    "ΔN",
+    "▲ {frp} MW"
+  ],
+  "ru": [
+    "AIS: --",
+    "AIS: {name}",
+    "CCTV",
+    "CRT",
+    "FLIR",
+    "GEO",
+    "Ironbow",
+    "Landsat 8/9",
+    "NAV",
+    "NVG",
+    "R&B",
+    "REC",
+    "VS",
+    "WHOT/BHOT"
+  ]
+}