v2.7.4: Named location presets and tappable nearest-airport ticker

Location presets can now optionally be given a name (e.g. "Home"),
shown in the overview instead of the raw coordinates. The
nearest-airport ticker on the Location Presets screen is now
tappable (shown with a thin green border) and adds that airport
directly as a new preset with its name and coordinates, using the
existing local airport database on the SD card - no internet lookup
needed. AirportLookup::findNearest() now also returns the found
airport's own lat/lon for this purpose.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/config.h

@@ -6,7 +6,7 @@ namespace Config {
     // CLAUDE.md-Workflow "Standard-Workflow: Push & Release") - erscheint
     // im Info-Screen (Menue > System > Info) und muss zum jeweiligen
     // Git-Tag passen.
-    constexpr const char* APP_VERSION = "2.7.3";
+    constexpr const char* APP_VERSION = "2.7.4";
 
     // Display-Helligkeit (Menue > System > Helligkeit), in Prozent.
     // MIN bewusst nicht 0 - ein komplett dunkles Display koennte sonst wie