Add geo‑tagged image overlay pipeline (Maps thumbnail, metadata burn, gallery save)

[krishna3554]

Motivation

• Provide a production-quality pipeline that, after an existing camera capture, permanently burns a modern geo-tag overlay (map thumbnail, coordinates, address, timestamp, placeholders, watermark) into the photo and saves the final image to the device gallery.
• Use high-accuracy location + reverse geocoding, a Google Static Maps thumbnail for visual context, and pixel-level compositing so the overlay is embedded into image bytes rather than only rendered in UI.

Description

• Added a new GeoPhotoModel and LocationService that perform high-accuracy GPS lookup, reverse geocoding, and robust error handling for GPS disabled, permission denied/deniedForever, timeouts, and other failures.
• Implemented GoogleMapService to build and download Google Static Maps thumbnails (uses google_static_maps_controller + http) with a graceful fallback when no API key or network is available, and added Android strings.xml/Manifest wiring for the Maps API key placeholder.
• Implemented ImageOverlayService (using the image package) plus ImageUtils to composite a dark rounded metadata card, embedded map thumbnail, address, lat/long, date/time, metric placeholders, and an app watermark directly into the photo pixels and write a final JPG to temp storage.
• Integrated gallery persistence via GalleryService (uses image_gallery_saver_plus), updated result flow in ResultScreen to generate the geo-tagged image, save it, display a processing UI and a saved banner, and return the saved gallery path; added on-screen preview widgets GeoInfoOverlay and MapPreviewWidget and minimal changes to existing camera flow to trigger location resolution after capture.
• Updated LocationInfo model to include extended metadata (altitude, speed, heading, place fields) and updated pubspec.yaml to include required packages plus Android manifest changes for Maps API key placeholder.

Testing

• Ran git diff --check to ensure no whitespace/merge issues and code changes were staged (succeeded in repo environment).
• Attempted flutter pub get and flutter analyze in the container but both could not run because Flutter is not installed in this environment (flutter: command not found).
• The pipeline is implemented with runtime fallbacks (map thumbnail optional) and explicit error messaging for location failures; please run flutter pub get, then test on an Android device/emulator with a valid Maps API key (set via android/app/src/main/res/values/strings.xml or --dart-define=GOOGLE_MAPS_API_KEY) to validate end-to-end behavior.

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Codex Task