feat(adsb): add IATA↔ICAO airline code translation for ACARS cross-linking

ACARS messages use IATA codes (e.g. UA2412) while ADS-B uses ICAO
callsigns (e.g. UAL2412). Add a translation layer so the two can
match, enabling click-to-highlight and datalink message correlation.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

utils/airline_codes.py

@@ -0,0 +1,161 @@
+"""IATA ↔ ICAO airline code mapping for flight number translation."""
+
+from __future__ import annotations
+
+import re
+
+# IATA (2-letter) → ICAO (3-letter) mapping for common airlines
+IATA_TO_ICAO: dict[str, str] = {
+    # North America — Major
+    "AA": "AAL",  # American Airlines
+    "DL": "DAL",  # Delta Air Lines
+    "UA": "UAL",  # United Airlines
+    "WN": "SWA",  # Southwest Airlines
+    "B6": "JBU",  # JetBlue Airways
+    "AS": "ASA",  # Alaska Airlines
+    "NK": "NKS",  # Spirit Airlines
+    "F9": "FFT",  # Frontier Airlines
+    "G4": "AAY",  # Allegiant Air
+    "HA": "HAL",  # Hawaiian Airlines
+    "SY": "SCX",  # Sun Country Airlines
+    "WS": "WJA",  # WestJet
+    "AC": "ACA",  # Air Canada
+    "WG": "WGN",  # Sunwing Airlines
+    "TS": "TSC",  # Air Transat
+    "PD": "POE",  # Porter Airlines
+    "MX": "MXA",  # Breeze Airways
+    "QX": "QXE",  # Horizon Air
+    "OH": "COM",  # PSA Airlines (Compass)
+    "OO": "SKW",  # SkyWest Airlines
+    "YX": "RPA",  # Republic Airways
+    "9E": "FLG",  # Endeavor Air (Pinnacle)
+    "CP": "CPZ",  # Compass Airlines
+    "PT": "SWQ",  # Piedmont Airlines
+    "MQ": "ENY",  # Envoy Air
+    "YV": "ASH",  # Mesa Airlines
+    "AX": "LOF",  # Trans States / GoJet
+    "ZW": "AWI",  # Air Wisconsin
+    "G7": "GJS",  # GoJet Airlines
+    "EV": "ASQ",  # ExpressJet / Atlantic Southeast
+    "AM": "AMX",  # Aeromexico
+    "VB": "VIV",  # VivaAerobus
+    "4O": "AIJ",  # Interjet
+    "Y4": "VOI",  # Volaris
+    # North America — Cargo
+    "5X": "UPS",  # UPS Airlines
+    "FX": "FDX",  # FedEx Express
+    # Europe — Major
+    "BA": "BAW",  # British Airways
+    "LH": "DLH",  # Lufthansa
+    "AF": "AFR",  # Air France
+    "KL": "KLM",  # KLM Royal Dutch
+    "IB": "IBE",  # Iberia
+    "AZ": "ITY",  # ITA Airways
+    "SK": "SAS",  # SAS Scandinavian
+    "AY": "FIN",  # Finnair
+    "OS": "AUA",  # Austrian Airlines
+    "LX": "SWR",  # Swiss International
+    "SN": "BEL",  # Brussels Airlines
+    "TP": "TAP",  # TAP Air Portugal
+    "EI": "EIN",  # Aer Lingus
+    "U2": "EZY",  # easyJet
+    "FR": "RYR",  # Ryanair
+    "W6": "WZZ",  # Wizz Air
+    "VY": "VLG",  # Vueling
+    "PC": "PGT",  # Pegasus Airlines
+    "TK": "THY",  # Turkish Airlines
+    "LO": "LOT",  # LOT Polish
+    "BT": "BTI",  # airBaltic
+    "DY": "NAX",  # Norwegian Air Shuttle
+    "VS": "VIR",  # Virgin Atlantic
+    "EW": "EWG",  # Eurowings
+    # Asia-Pacific — Major
+    "SQ": "SIA",  # Singapore Airlines
+    "CX": "CPA",  # Cathay Pacific
+    "QF": "QFA",  # Qantas
+    "JL": "JAL",  # Japan Airlines
+    "NH": "ANA",  # All Nippon Airways
+    "KE": "KAL",  # Korean Air
+    "OZ": "AAR",  # Asiana Airlines
+    "CI": "CAL",  # China Airlines
+    "BR": "EVA",  # EVA Air
+    "CZ": "CSN",  # China Southern
+    "MU": "CES",  # China Eastern
+    "CA": "CCA",  # Air China
+    "AI": "AIC",  # Air India
+    "GA": "GIA",  # Garuda Indonesia
+    "TG": "THA",  # Thai Airways
+    "MH": "MAS",  # Malaysia Airlines
+    "PR": "PAL",  # Philippine Airlines
+    "VN": "HVN",  # Vietnam Airlines
+    "NZ": "ANZ",  # Air New Zealand
+    "3K": "JSA",  # Jetstar Asia
+    "JQ": "JST",  # Jetstar Airways
+    "AK": "AXM",  # AirAsia
+    "TR": "TGW",  # Scoot
+    "5J": "CEB",  # Cebu Pacific
+    # Middle East / Africa
+    "EK": "UAE",  # Emirates
+    "QR": "QTR",  # Qatar Airways
+    "EY": "ETD",  # Etihad Airways
+    "GF": "GFA",  # Gulf Air
+    "SV": "SVA",  # Saudia
+    "ET": "ETH",  # Ethiopian Airlines
+    "MS": "MSR",  # EgyptAir
+    "SA": "SAA",  # South African Airways
+    "RJ": "RJA",  # Royal Jordanian
+    "WY": "OMA",  # Oman Air
+    # South America
+    "LA": "LAN",  # LATAM Airlines
+    "G3": "GLO",  # Gol Transportes Aéreos
+    "AD": "AZU",  # Azul Brazilian Airlines
+    "AV": "AVA",  # Avianca
+    "CM": "CMP",  # Copa Airlines
+    "AR": "ARG",  # Aerolíneas Argentinas
+    # ACARS-specific addressing codes
+    "MC": "MCO",  # Possible: some ACARS systems use MC
+}
+
+# Build reverse mapping (ICAO → IATA)
+ICAO_TO_IATA: dict[str, str] = {v: k for k, v in IATA_TO_ICAO.items()}
+
+# Regex to split flight number into airline prefix and numeric part
+_FLIGHT_RE = re.compile(r'^([A-Z]{2,3})(\d+[A-Z]?)$')
+
+
+def translate_flight(flight: str) -> list[str]:
+    """Translate a flight number to all possible equivalent forms.
+
+    Given "UA2412" (IATA), returns ["UAL2412"] (ICAO).
+    Given "UAL2412" (ICAO), returns ["UA2412"] (IATA).
+    Returns empty list if no translation found.
+    """
+    if not flight:
+        return []
+
+    upper = flight.strip().upper()
+    m = _FLIGHT_RE.match(upper)
+    if not m:
+        return []
+
+    prefix, number = m.group(1), m.group(2)
+    results = []
+
+    # Try IATA → ICAO
+    if prefix in IATA_TO_ICAO:
+        results.append(IATA_TO_ICAO[prefix] + number)
+
+    # Try ICAO → IATA
+    if prefix in ICAO_TO_IATA:
+        results.append(ICAO_TO_IATA[prefix] + number)
+
+    return results
+
+
+def expand_search_terms(terms: set[str]) -> set[str]:
+    """Expand a set of callsign/flight search terms with translated variants."""
+    expanded = set(terms)
+    for term in list(terms):
+        for translated in translate_flight(term):
+            expanded.add(translated)
+    return expanded