perf(android): R8, bitmap downscaling, edge-to-edge; recover device compat; publish to production

Device compatibility (regression fix):
- The CAMERA permission (from zxing_barcode_scanner / image_picker) implicitly
  required android.hardware.camera, excluding camera-less devices — Play showed
  Automotive -96%, Chromebook -86%, TV -25%. Declare camera & location
  uses-feature required="false" to keep those devices supported.
- Detect a real camera at runtime (PackageManager.FEATURE_CAMERA_ANY via the
  existing MethodChannel), cache it at bootstrap, and hide the QR scan button and
  the camera photo-source option when absent, so no broken actions are offered.

Play "app optimization" recommendations:
- Enable R8 (isMinifyEnabled + isShrinkResources) with keep rules for the
  OCR (tesseract4android), SQLCipher and notifications JNI/reflection code.
- Bitmap downscaling: cacheWidth/cacheHeight (and ResizeImage for avatars) on
  list thumbnails and avatars so photos decode to on-screen size, not full res.
- Edge-to-edge: opt in with transparent system bars in main().

Release flow:
- Tagged builds now publish to the production track at 100% (was internal);
  add a manual deploy_internal lane as a QA safety net.
- Document country/region availability as a Play Console setting (not in-repo).

apps/app_seeds/lib/ui/draft_triage.dart

@@ -108,6 +108,10 @@ class _DraftTile extends StatelessWidget {
                 photo,
                 width: 48,
                 height: 48,
+                cacheWidth:
+                    (48 * MediaQuery.devicePixelRatioOf(context)).round(),
+                cacheHeight:
+                    (48 * MediaQuery.devicePixelRatioOf(context)).round(),
                 fit: BoxFit.cover,
               ),
             ),
@@ -192,6 +196,8 @@ class _NameDraftDialogState extends State<NameDraftDialog> {
               child: Image.memory(
                 widget.photo!,
                 height: 140,
+                cacheHeight:
+                    (140 * MediaQuery.devicePixelRatioOf(context)).round(),
                 fit: BoxFit.cover,
               ),
             ),