Revert Sound feature (hardware EMI noise, not fixable in firmware); keep preset auto-activate fix and QR-on-main-screen layout

Root-caused to SPI bus crosstalk from TFT/touch during radar-sweep
redraws - muting the software output did not silence the residual
hiss, confirming this is hardware EMI rather than a firmware logic
bug. All Sound-related files, settings, i18n strings, and menu
entries have been removed.

Unrelated fixes from the same session are kept: newly created
location presets (via address search, manual coordinates, or the
nearest-airport ticker) now activate immediately instead of leaving
the previous location active; the WebUI QR code moved from a
separate sub-screen onto the main info screen, centered under the
explanatory text.

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

src/address_search_screen.cpp

@@ -610,7 +610,12 @@ bool run(TFT_eSPI& tft) {
         if (choice == 0) continue;
 
         String name = runNameKeypad(tft);
-        return LocationPresets::addPreset(lat, lon, name);
+        if (!LocationPresets::addPreset(lat, lon, name)) return false;
+        // Neu angelegtes Preset sofort aktivieren - sonst blieb z.B. der
+        // automatische IP-Standort aktiv, obwohl gerade extra eine genauere
+        // Adresse eingegeben wurde (siehe Alex' Feedback).
+        LocationPresets::setActiveIndex((int8_t)(LocationPresets::count() - 1));
+        return true;
     }
 }