docs(i18n): Arabic language notes and right-to-left guidance

- docs/translations/ar.md: style, Western digits and direction, units,
  the six plural forms and the glossary.
- TRANSLATORS.md and CURRENT-STATE.md list Arabic and say how a
  right-to-left language mirrors the chrome.

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

docs/CURRENT-STATE.md

@@ -3733,7 +3733,7 @@ test:track` 43 tracking invariants · headless QA harnesses under
 
 ### Interface localization (October 2026)
 
-Shipped locales: **en** (source and fallback), **es**, **ru**, **zh-CN** and **zh-Hant**. The code lives in
+Shipped locales: **en** (source and fallback), **ar**, **es**, **ru**, **zh-CN** and **zh-Hant**. The code lives in
 `src/i18n/`. How to mark UI text: [`docs/I18N.md`](./I18N.md); translator workflow:
 [`docs/TRANSLATORS.md`](./TRANSLATORS.md).
 
@@ -3747,11 +3747,19 @@ Shipped locales: **en** (source and fallback), **es**, **ru**, **zh-CN** and **z
   `navigator.languages` → English. Chinese tags default to `zh-CN`; Traditional Chinese tags
   select `zh-Hant`. Explicit `Hans` selects `zh-CN` regardless of region. `?lang=` is not stored, and share links drop
   it, so a recipient keeps their own language. The globe picker in the
-  bottom-right corner (`src/ui/localePicker.js`) stores the choice, drops
+  bottom-right corner (bottom-left in Arabic) (`src/ui/localePicker.js`) stores the choice, drops
   `?lang=` (keeps it only when storage is blocked) and reloads. It asks first
   when the reload would lose work registered with `registerUnsavedWork`:
   unsaved keys or CCTV calibration, Draw marks, imported map files, the open
   cockpit, a voice session.
+- **Right to left.** Arabic (`ar`) is in `RTL_LOCALES`, so `<html dir="rtl">`:
+  the title, style indicator and both rails swap sides through logical
+  properties (`inset-inline-*`, `margin-inline-*`), the dock and corner row
+  reverse their order, and `src/ui/styles/rtl.css` holds the rest: no
+  letter-spacing on Arabic text, Noto Sans Arabic in the font stacks, the intel
+  HUD kept as a left-to-right instrument overlay, media transport and the radio
+  dial kept left to right. Intl formatters get `ar-u-nu-latn`, so numbers and
+  dates keep Western digits.
 - **Gate.** `npm run i18n` (and `src/i18n/catalog.test.mjs` under `npm test`)
   extracts every message and fails on missing, empty, unused,
   placeholder-mismatched, still-English (plural forms included) or

docs/TRANSLATORS.md

@@ -1,6 +1,6 @@
 # Translating God's Eye View
 
-Shipped languages: **English** (source and fallback), **Spanish** (`es`), **Russian** (`ru`), **Simplified Chinese** (`zh-CN`) and **Traditional Chinese** (`zh-Hant`).
+Shipped languages: **English** (source and fallback), **Arabic** (`ar`), **Spanish** (`es`), **Russian** (`ru`), **Simplified Chinese** (`zh-CN`) and **Traditional Chinese** (`zh-Hant`).
 
 ## How it works
 
@@ -44,7 +44,7 @@ Edit `src/i18n/locales/<code>.json` and run `npm run i18n`. To see your change,
 
 1. Create `src/i18n/locales/<code>.json`, fill it from `npm run i18n -- --missing <code>` (start from `{}`), and translate every entry.
 2. Import it in `src/i18n/index.js` and add it to `CATALOGS`.
-3. Add the code to `LOCALES` and its own-language name to `LOCALE_NAMES` in `src/i18n/locale.js`. Right-to-left languages also go in `RTL_LOCALES`.
+3. Add the code to `LOCALES` and its own-language name to `LOCALE_NAMES` in `src/i18n/locale.js`. Right-to-left languages also go in `RTL_LOCALES`; the chrome mirrors through logical CSS properties (`inset-inline-*`, `margin-inline-*`), and `src/ui/styles/rtl.css` holds what those cannot express (see the Arabic notes). If the language should keep Western digits, map it in `INTL_TAGS` in `locale.js`.
 4. Add `src/i18n/locales/<code>.json` next to `ru.json` in `scripts/package-boundaries.json`.
 5. Write `docs/translations/<code>.md`: glossary, plural forms, units and style (copy the structure of `ru.md`).
 6. Run `npm run i18n` and `npm test`, then check the panels in the app at narrow widths.
@@ -63,4 +63,4 @@ These are contracts, not copy: layer ids and registry keys, status enums and oth
 
 ## Language notes
 
-Each language keeps its glossary, plural forms, units and style in its own file, `docs/translations/<code>.md`: [Spanish](./translations/es.md), [Russian](./translations/ru.md), [Simplified Chinese](./translations/zh-CN.md), [Traditional Chinese](./translations/zh-Hant.md). Read it before translating, and add a term there when you settle on one.
+Each language keeps its glossary, plural forms, units and style in its own file, `docs/translations/<code>.md`: [Arabic](./translations/ar.md), [Spanish](./translations/es.md), [Russian](./translations/ru.md), [Simplified Chinese](./translations/zh-CN.md), [Traditional Chinese](./translations/zh-Hant.md). Read it before translating, and add a term there when you settle on one.

docs/translations/ar.md

@@ -0,0 +1,92 @@
+# Arabic (`ar`)
+
+Catalog: `src/i18n/locales/ar.json`. General rules: [TRANSLATORS.md](../TRANSLATORS.md).
+
+Translation sources: abiyeenzo (#915).
+
+## Style
+
+- Modern Standard Arabic, neutral across regions. Address the user with plain imperatives: «انقر»، «فعّل»، «أعد المحاولة».
+- Arabic has no letter case: an UPPERCASE English HUD label becomes the same short Arabic label. Keep labels as short as the English: «مباشر»، «متقادم»، «متوقف».
+- Status words in progress use «جارٍ …» («جارٍ التحميل»); finished actions use the passive («تم الحفظ»، «أُلغي التحميل»).
+- Arabic punctuation in Arabic text: ، ؛ ؟ and «» for quotes. Keep `·` as the HUD separator, `—` with spaces, and `…`.
+- Arrows that show a sequence point the way Arabic reads: «الإشارات ← الأخبار ← المحلي», «{origin} ← {destination}».
+- Product names, provider names and codes stay in Latin letters: Google, Cesium ion, CelesTrak, NOAA, FIRMS, AIS, ADS-B, GNSS, CCTV, HUD, CRT, NVG, FLIR, WHOT/BHOT, Ironbow, Street View, Mapillary. Aviation and camera abbreviations stay Latin too: HDG, FOV, BRG, CRS, GS, TRK, V/S, SQUAWK. Local place names from the Bhote Koshi scene (Rasuwagadhi, Bidur, Timure…) stay Latin; well-known cities and countries are written in Arabic (أوستن، طوكيو، نيبال).
+- Months are the international names used across the Arab world: يناير، فبراير … أغسطس.
+
+## Digits and direction
+
+- **Western digits (0–9)**, as in the catalog. The HUD reads like an instrument panel, and mixing ٠–٩ with Latin codes and coordinates misreads. `intlLocale('ar')` in `src/i18n/locale.js` passes `ar-u-nu-latn` to every Intl formatter, so browsers that default to Arabic-Indic digits for an Arabic region still show 0–9.
+- **Right to left.** `ar` is in `RTL_LOCALES`, so the page gets `<html dir="rtl">`. The title, style indicator and both rails swap sides; the dock and the corner row reverse. The intel HUD (classification block, MGRS, coordinates, GSD) stays a left-to-right instrument overlay; its translated lines read right to left inside it. Media transport (previous / play / next) and the radio dial stay left to right, as on any player. Layout rules: `src/ui/styles/rtl.css`.
+- Latin runs inside Arabic sentences (product names, codes, `{placeholders}` filled with English data) are isolated by the bidi algorithm; write them as plain text, without manual direction marks.
+
+## Units
+
+Distances and speeds take Arabic abbreviations after the number, with a space: كم، م، كم/س، كم/ث، م/ث، ميل/س، عقدة (knots)، قدم (feet)، مم. Time: ث (seconds)، د (minutes)، س (hours)، يوم. Scientific and radio units stay Latin: MHz، dB، dBFS، dBZ، hPa، MW، MiB. `°` and `%` stay. Hemisphere letters in coordinates: ش (N)، ج (S)، ق (E)، غ (W), as in `21.33ش`.
+
+## Plurals
+
+`Intl.PluralRules('ar')` uses all six CLDR categories, and a `tn()` entry needs every one:
+
+| Form    | Counts                      | Example       |
+| ------- | --------------------------- | ------------- |
+| `zero`  | 0                           | 0 مصدر        |
+| `one`   | 1                           | مصدر واحد (1) |
+| `two`   | 2                           | مصدران (2)    |
+| `few`   | 3–10, 103–110…              | 3 مصادر       |
+| `many`  | 11–99, 111–199…             | 11 مصدرًا     |
+| `other` | 100–102, 200–202, fractions | 100 مصدر      |
+
+Every form must keep `{count}`. For one and two, Arabic names the quantity with the noun itself (مصدر واحد، مصدران), so the number follows in parentheses. `few` takes the plural noun; `many` the accusative singular (مصدرًا، مفتاحًا); `zero` and `other` the genitive singular. When a word next to the number cannot agree in every form, or a short chip has no room, put the number after a colon instead: «القريبة: {count}»، «الملفات المحددة: {count}».
+
+## Glossary
+
+| English                                   | العربية                                                   |
+| ----------------------------------------- | --------------------------------------------------------- |
+| layer / data layer                        | طبقة / طبقة بيانات                                        |
+| feed / source                             | مصدر بيانات (short: مصدر) / مصدر                          |
+| LIVE (status) / live data                 | مباشر / البيانات المباشرة (not حي)                        |
+| SIMULATED                                 | محاكى (status) / محاكاة                                   |
+| stale / degraded / unavailable            | متقادم / متدهور / غير متاح                                |
+| ON / OFF (state)                          | مفعّل / متوقف                                             |
+| retry                                     | إعادة المحاولة                                            |
+| key (API key) / POWER UP                  | مفتاح (مفتاح API) / تشغيل                                 |
+| Provider Settings                         | إعدادات المزوّدين                                         |
+| globe / map / map source / basemap        | الكرة الأرضية / الخريطة / مصدر الخريطة / الخريطة الأساسية |
+| tiles                                     | بلاطات                                                    |
+| aircraft / flight / military flights      | طائرة / رحلة / الرحلات العسكرية                           |
+| vessel, ship                              | سفينة                                                     |
+| satellite                                 | قمر صناعي                                                 |
+| launch (rocket) / space mission           | إطلاق / مهمة فضائية                                       |
+| contact (tracked object)                  | هدف                                                       |
+| installation, site / mapped               | منشأة، موقع / مرسوم                                       |
+| camera / CCTV camera                      | كاميرا / كاميرا CCTV                                      |
+| earthquake / active fire / fire perimeter | زلزال / حريق نشط / محيط حريق                              |
+| cyclone advisory                          | نشرة إعصار                                                |
+| scene / shot / scene recipe               | مشهد / لقطة / قالب المشهد                                 |
+| briefing / panel / dock                   | إحاطة / لوحة / الشريط السفلي                              |
+| preset / visual preset                    | إعداد مسبق / نمط بصري                                     |
+| Scope (circular viewport mask) / keyhole  | المنظار / الفتحة                                          |
+| Clean UI                                  | واجهة نظيفة                                               |
+| cockpit                                   | القمرة (قمرة القيادة)                                     |
+| heading / altitude / ground speed         | الاتجاه (HDG) / الارتفاع / السرعة الأرضية                 |
+| Street Level / Street View                | مستوى الشارع / Street View                                |
+| Recent Imagery                            | الصور الحديثة                                             |
+| Global Context / Context                  | السياق العالمي / السياق                                   |
+| radio station / tuner / gain              | محطة / موالف / الكسب                                      |
+| decoder (SDR)                             | مفكّك                                                     |
+| transit / bike share                      | النقل العام / الدراجات المشتركة                           |
+| Previous / Next                           | السابق / التالي                                           |
+| compass points (N, NNE, …)                | شمال، شمال شمال شرق، …                                    |
+| forecast / valid / issued                 | توقع / صالح حتى / صدر                                     |
+| observation / observed                    | رصد / مرصود                                               |
+| field (weather) / model                   | حقل / نموذج                                               |
+| scene cloud                               | غيوم المشهد                                               |
+| box (Recent Imagery area) / pin           | منطقة / تثبيت                                             |
+| THIS (voice pointer)                      | المُشار إليه                                              |
+| outline / mark (map annotation)           | مخطط / علامة، تعليم                                       |
+| share (a view or link)                    | مشاركة                                                    |
+| AI agent                                  | وكيل ذكاء اصطناعي                                         |
+| stage (rocket) / downrange                | مرحلة / على امتداد المسار                                 |
+| frame (bring into view)                   | إظهار في الإطار                                           |
+| story beat                                | مرحلة القصة                                               |