Add native address search with geocoding for location presets, remove itilog.com link

Adds a new AddressSearchScreen: enter an address on a dedicated
keyboard (with a special-character page for common European accented
letters), geocode it via the free OpenStreetMap Nominatim service,
confirm the found place, optionally name it, and save it as a new
location preset - no external website needed anymore.

Reachable both from Location Presets > "+" (choice between "by
address" and manual coordinates) and, for new users, from a one-time
FirstRunLocationScreen shown right after the language picker on first
boot, explaining why an exact address beats automatic IP geolocation
and letting them set it up immediately (skippable).

Removes the itilog.com link/tip added in the previous commit (Location
Presets info screen, all 6 languages, and the README) - superseded by
this native in-app flow.

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

README.md

@@ -23,10 +23,6 @@ You can flash the firmware directly from your browser to your CYD display withou
 2. Insert a FAT32-formatted microSD card into your display.
 3. On first boot: Calibrate the touchscreen and configure your Wi-Fi via the built-in on-screen keyboard.
 
-**Tip:** for the best experience, set your exact location as a Location Preset (Menu → Flight Options → Location Presets) instead of relying on automatic IP-based geolocation. IP geolocation can easily be off by 20-30 km - you might hear a plane outside your window while the radar screen stays empty because the device thinks you're somewhere else entirely.
-
-To get your exact coordinates for free, visit [itilog.com](https://www.itilog.com/), enter your address, and copy the resulting latitude/longitude into a new Location Preset. With your precise location set, the proximity LED blinks in sync with aircraft you can actually hear overhead.
-
 ---
 
 ## Features