i18n: add Swedish (sv)

Adds a complete Swedish catalog (2,961 messages) and registers sv in the
locale list, catalogs, language picker and package boundaries. Browsers set
to Swedish get it at once; ?lang=sv or the language picker choose it
elsewhere. Numbers and dates come out Swedish from Intl.

- docs/translations/sv.md: style (imperative without a pronoun, closed
  compounds, decimal comma, space before units and %) and the glossary.
- Entries that stay identical to English on purpose (codes such as HDG and
  FOV, product, place and source names) are listed under sv in
  same-as-english.json.
- The picker-order test places Svenska after Português.
- docs/CURRENT-STATE.md and docs/TRANSLATORS.md list the new language.

The translation comes from God's Eye View Sverige, a Swedish fork, and was
brought up to date with main (wildlife sightings, event age filter, traffic
styles and the rest).

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/i18n/index.js

@@ -26,6 +26,7 @@ import it from './locales/it.json' with { type: 'json' };
 import ja from './locales/ja.json' with { type: 'json' };
 import pt from './locales/pt.json' with { type: 'json' };
 import ru from './locales/ru.json' with { type: 'json' };
+import sv from './locales/sv.json' with { type: 'json' };
 import uk from './locales/uk.json' with { type: 'json' };
 import zhCN from './locales/zh-CN.json' with { type: 'json' };
 import zhHant from './locales/zh-Hant.json' with { type: 'json' };
@@ -39,6 +40,7 @@ const CATALOGS = Object.freeze({
   ja,
   pt,
   ru,
+  sv,
   uk,
   'zh-CN': zhCN,
   'zh-Hant': zhHant,

src/i18n/locale.js

@@ -18,6 +18,7 @@ export const LOCALES = Object.freeze([
   'ja',
   'pt',
   'ru',
+  'sv',
   'uk',
   'zh-CN',
   'zh-Hant',
@@ -34,6 +35,7 @@ export const LOCALE_NAMES = Object.freeze({
   ja: '日本語',
   pt: 'Português (Brasil)',
   ru: 'Русский',
+  sv: 'Svenska',
   uk: 'Українська',
   'zh-CN': '中文（简体）',
   'zh-Hant': '中文（繁體）',

src/i18n/same-as-english.json

@@ -944,6 +944,169 @@
     "iNaturalist",
     "iNaturalist ↗"
   ],
+  "sv": [
+    "STATION",
+    "NAV",
+    "GEO",
+    "SAR",
+    "CRT",
+    "NVG",
+    "FLIR",
+    "REC",
+    "AIS: --",
+    "HDG {value}°",
+    "BRG {value}°",
+    "BRG —",
+    "CRS {value}°",
+    "Station {id}",
+    "Station",
+    "FOV {value}°",
+    "▲ {frp} MW",
+    "T−{time} · {mission}",
+    "{value} KM",
+    "{value} KM/S",
+    "STATUS · ",
+    "DESTINATION",
+    "STATUS",
+    "T minus {seconds}",
+    "Ambient",
+    "Blues",
+    "Country",
+    "Dance",
+    "Folk",
+    "Funk",
+    "House",
+    "Indie",
+    "Jazz",
+    "Latin",
+    "Metal",
+    "Oldies",
+    "Pop",
+    "Punk",
+    "R&B",
+    "Reggae",
+    "Rock",
+    "Soul",
+    "Techno",
+    "Trance",
+    "AIS: {name}",
+    "{type}  SPD: {speed}  HDG: {heading}",
+    "POS: LIVE",
+    "POS: {time}Z",
+    "Bloom",
+    "{domain} · {age}",
+    "{cohort} · {contact}",
+    "{side} {angle}",
+    "DEST {bearing}",
+    "Normal",
+    "Anime",
+    "Noir",
+    "{aircraftClass} · {distance}",
+    "CCTV",
+    "Radio",
+    "{state} · {source}",
+    "{state} · {source} · {detail}",
+    "{source} · {loadingLabel}",
+    "{state} · {source} · {detail} · {ago}",
+    "{state} · {source} · {ago}",
+    "{source} · {ago}",
+    "{name}: {state}",
+    "DEST ---°",
+    "TEMP",
+    "RADIO",
+    "COCKPIT",
+    "Layout",
+    "Minimal",
+    "Scope",
+    "{speed} kn",
+    "NORMAL",
+    "ANIME",
+    "NOIR",
+    "view band|GLOBAL",
+    "{distance} · {duration} · {mode}",
+    "S2 · {name}",
+    "1090 MHz",
+    "978 MHz UAT",
+    "V/S {rate}",
+    "POSITION {age}",
+    "fire behavior|Minimal",
+    "{county} County",
+    "Sentinel-2",
+    "Sentinel-2 via HLS",
+    "Landsat 8/9",
+    "Landsat 8/9 via HLS",
+    "Google Street View",
+    "GOOGLE STREET VIEW",
+    "Hybrid",
+    "{state} · {time} · {lag}",
+    "{state}: {time}",
+    "RADAR · {units}",
+    "REGION",
+    "FILTER",
+    "{source} HTTP {status}",
+    "N",
+    "S",
+    "WHOT/BHOT",
+    "Ironbow",
+    "HDG",
+    "FOV",
+    "ΔN",
+    "LIVE",
+    "OK",
+    "{value} KM/H",
+    "SQUAWK {code} · {status}",
+    "{aircraftClass} · {emergency} · {feedState}",
+    "S2 GhostMaps",
+    "NASA FIRMS · LIVE",
+    "feed status|live",
+    "DSP {count} blocks",
+    "Austin",
+    "San Francisco",
+    "New York",
+    "Tokyo",
+    "London",
+    "Paris",
+    "Dubai",
+    "Washington DC",
+    "Tallinn",
+    "Los Angeles",
+    "{category} ({count})",
+    "A / B",
+    "km/h",
+    "m/s",
+    "mph",
+    "hPa",
+    "ft",
+    "km",
+    "m",
+    "h",
+    "min",
+    "s",
+    "dB",
+    "STD",
+    "Plan",
+    "MINI",
+    "standard",
+    "mini",
+    "STANDARD",
+    "{items} {scope}",
+    "FT",
+    "MIL",
+    "MM",
+    "SIG",
+    "AUTO",
+    "FM MHZ",
+    "Cyber",
+    "Sonar",
+    "Cyan",
+    "≥ {value} MW",
+    "{count} {kind}",
+    "Be Whale Wise",
+    "Salish Sea",
+    "Acartia",
+    "CC BY 4.0",
+    "iNaturalist"
+  ],
   "uk": [
     "AIS: --",
     "AIS: {name}",

src/ui/localePicker.test.mjs

@@ -52,6 +52,7 @@ test('the current language comes first, the rest by their own names', () => {
       'fr',
       'it',
       'pt',
+      'sv',
       'ar',
       'zh-CN',
       'zh-Hant',
@@ -73,6 +74,7 @@ test('the current language comes first, the rest by their own names', () => {
       'fr',
       'it',
       'pt',
+      'sv',
       'ru',
       'uk',
       'ar',
@@ -96,6 +98,7 @@ test('the current language comes first, the rest by their own names', () => {
       'fr',
       'it',
       'pt',
+      'sv',
       'ru',
       'uk',
       'ar',
@@ -120,6 +123,7 @@ test('the current language comes first, the rest by their own names', () => {
       'fr',
       'it',
       'pt',
+      'sv',
       'ru',
       'uk',
       'zh-CN',