Enhance aircraft details display to match dump1090 format

- Add country lookup from ICAO hex codes with flag display
- Implement UTC clocks and last update time indicators
- Enhance aircraft table with ICAO, squawk, and RSSI columns
- Add color-coded RSSI signal strength indicators
- Fix calculateDistance returning string instead of number
- Accept all SBS-1 message types for complete data capture
- Improve data merging to preserve country and registration

🤖 Generated with [Claude Code](https://claude.ai/code)

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

internal/parser/sbs1.go

@@ -30,6 +30,9 @@ type Aircraft struct {
 	LastSeen    time.Time    `json:"last_seen"`
 	Messages    int          `json:"messages"`
 	TrackHistory []TrackPoint `json:"track_history,omitempty"`
+	RSSI        float64      `json:"rssi,omitempty"`
+	Country     string       `json:"country,omitempty"`
+	Registration string      `json:"registration,omitempty"`
 }
 
 type AircraftData struct {
@@ -44,10 +47,10 @@ func ParseSBS1Line(line string) (*Aircraft, error) {
 		return nil, nil
 	}
 
-	messageType := parts[1]
-	if messageType != "1" && messageType != "3" && messageType != "4" {
-		return nil, nil
-	}
+	// messageType := parts[1]
+	// Accept all message types to get complete data
+	// MSG types: 1=ES_IDENT_AND_CATEGORY, 2=ES_SURFACE_POS, 3=ES_AIRBORNE_POS
+	// 4=ES_AIRBORNE_VEL, 5=SURVEILLANCE_ALT, 6=SURVEILLANCE_ID, 7=AIR_TO_AIR, 8=ALL_CALL_REPLY
 
 	aircraft := &Aircraft{
 		Hex:      strings.TrimSpace(parts[4]),
@@ -55,6 +58,8 @@ func ParseSBS1Line(line string) (*Aircraft, error) {
 		Messages: 1,
 	}
 
+	// Different message types contain different fields
+	// Always try to extract what's available
 	if parts[10] != "" {
 		aircraft.Flight = strings.TrimSpace(parts[10])
 	}
@@ -72,8 +77,8 @@ func ParseSBS1Line(line string) (*Aircraft, error) {
 	}
 
 	if parts[13] != "" {
-		if track, err := strconv.Atoi(parts[13]); err == nil {
-			aircraft.Track = track
+		if track, err := strconv.ParseFloat(parts[13], 64); err == nil {
+			aircraft.Track = int(track)
 		}
 	}
 
@@ -100,6 +105,121 @@ func ParseSBS1Line(line string) (*Aircraft, error) {
 		aircraft.OnGround = parts[21] == "1"
 	}
 
+	aircraft.Country = getCountryFromICAO(aircraft.Hex)
+	aircraft.Registration = getRegistrationFromICAO(aircraft.Hex)
+
 	return aircraft, nil
 }
 
+func getCountryFromICAO(icao string) string {
+	if len(icao) < 6 {
+		return "Unknown"
+	}
+
+	prefix := icao[:1]
+	
+	switch prefix {
+	case "4":
+		return getCountryFrom4xxxx(icao)
+	case "A":
+		return "United States"
+	case "C":
+		return "Canada"
+	case "D":
+		return "Germany"
+	case "F":
+		return "France"
+	case "G":
+		return "United Kingdom"
+	case "I":
+		return "Italy"
+	case "J":
+		return "Japan"
+	case "P":
+		return getPCountry(icao)
+	case "S":
+		return getSCountry(icao)
+	case "O":
+		return getOCountry(icao)
+	default:
+		return "Unknown"
+	}
+}
+
+func getCountryFrom4xxxx(icao string) string {
+	if len(icao) >= 2 {
+		switch icao[:2] {
+		case "40":
+			return "United Kingdom"
+		case "44":
+			return "Austria"
+		case "45":
+			return "Denmark"
+		case "46":
+			return "Germany"
+		case "47":
+			return "Germany"
+		case "48":
+			return "Netherlands"
+		case "49":
+			return "Netherlands"
+		}
+	}
+	return "Europe"
+}
+
+func getPCountry(icao string) string {
+	if len(icao) >= 2 {
+		switch icao[:2] {
+		case "PH":
+			return "Netherlands"
+		case "PJ":
+			return "Netherlands Antilles"
+		}
+	}
+	return "Unknown"
+}
+
+func getSCountry(icao string) string {
+	if len(icao) >= 2 {
+		switch icao[:2] {
+		case "SE":
+			return "Sweden"
+		case "SX":
+			return "Greece"
+		}
+	}
+	return "Unknown"
+}
+
+func getOCountry(icao string) string {
+	if len(icao) >= 2 {
+		switch icao[:2] {
+		case "OO":
+			return "Belgium"
+		case "OH":
+			return "Finland"
+		}
+	}
+	return "Unknown"
+}
+
+func getRegistrationFromICAO(icao string) string {
+	// This is a simplified conversion - real registration lookup would need a database
+	country := getCountryFromICAO(icao)
+	switch country {
+	case "Germany":
+		return "D-" + icao[2:]
+	case "United Kingdom":
+		return "G-" + icao[2:]
+	case "France":
+		return "F-" + icao[2:]
+	case "Netherlands":
+		return "PH-" + icao[2:]
+	case "Sweden":
+		return "SE-" + icao[2:]
+	default:
+		return icao
+	}
+}
+