i18n(ar): register Arabic as the first right-to-left language

- Add ar to LOCALES (picker name العربية) and RTL_LOCALES, so <html dir>
  turns rtl; any ar-* tag maps to it.
- Intl formatters get ar-u-nu-latn: numbers and dates keep Western digits
  like the catalog, whatever the browser's ICU picks for Arabic regions.
- HUD quantities keep a space before an Arabic unit (2069.0 كم), as in
  Chinese, instead of running digits into the word.
- Codes and product names that stay Latin go to same-as-english.json.

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

src/i18n/same-as-english.json

@@ -1,4 +1,38 @@
 {
+  "ar": [
+    "1090 MHz",
+    "978 MHz UAT",
+    "AIS: --",
+    "AIS: {name}",
+    "BRG {value}°",
+    "BRG —",
+    "CAL {value}",
+    "CAL · {badge}",
+    "CCTV",
+    "CRS {value}°",
+    "CRT",
+    "FLIR",
+    "FOV",
+    "FOV {value}°",
+    "GEO",
+    "GOOGLE STREET VIEW",
+    "Google Street View",
+    "HDG",
+    "HDG {value}°",
+    "Ironbow",
+    "Landsat 8/9",
+    "NVG",
+    "REC",
+    "S2 GhostMaps",
+    "SQUAWK {code} · {status}",
+    "SRC {value}",
+    "Sentinel-2",
+    "WHOT/BHOT",
+    "dB",
+    "hPa",
+    "{source} HTTP {status}",
+    "▲ {frp} MW"
+  ],
   "es": [
     "1090 MHz",
     "978 MHz UAT",