v2.0: Full localization (6 languages), first-run language screen, aircraft detail overhaul, aircraft-model API fallback, and multiple bugfixes

src/airline_filter.h

@@ -0,0 +1,16 @@
+#pragma once
+#include <Arduino.h>
+
+namespace AirlineFilter {
+    constexpr uint8_t MAX_HIDDEN = 10;
+
+    void init();
+
+    uint8_t count();
+    String icaoAt(uint8_t index);
+
+    bool addHidden(const char* icaoPrefix);
+    void removeHidden(uint8_t index);
+
+    bool isHidden(const char* callsign);
+}