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/calendar_screen.dart

@@ -235,8 +235,14 @@ class _CalendarRow extends StatelessWidget {
       leading: CircleAvatar(
         radius: 20,
         backgroundColor: swatch.fill,
-        foregroundImage:
-            entry.photo == null ? null : MemoryImage(entry.photo!),
+        // Decode to the 40px avatar size (× dpr), not the full photo.
+        foregroundImage: entry.photo == null
+            ? null
+            : ResizeImage(
+                MemoryImage(entry.photo!),
+                width: (40 * MediaQuery.devicePixelRatioOf(context)).round(),
+                height: (40 * MediaQuery.devicePixelRatioOf(context)).round(),
+              ),
         child: entry.photo == null
             ? Text(
                 entry.label.isEmpty

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,
               ),
             ),

apps/app_seeds/lib/ui/market_widgets.dart

@@ -36,6 +36,7 @@ class OfferThumbnail extends StatelessWidget {
     return ClipRRect(
       borderRadius: BorderRadius.circular(10),
       child: _offerImage(
+        context,
         url,
         semanticLabel: semanticLabel,
         width: size,
@@ -63,7 +64,7 @@ class OfferHeroImage extends StatelessWidget {
       borderRadius: BorderRadius.circular(14),
       child: AspectRatio(
         aspectRatio: 4 / 3,
-        child: _offerImage(url, semanticLabel: semanticLabel),
+        child: _offerImage(context, url, semanticLabel: semanticLabel),
       ),
     );
   }
@@ -73,6 +74,7 @@ class OfferHeroImage extends StatelessWidget {
 /// remote URL (via network), always cropping to fill and falling back to a
 /// neutral placeholder — a broken image must never block the card.
 Widget _offerImage(
+  BuildContext context,
   String url, {
   required String semanticLabel,
   double? width,
@@ -80,10 +82,16 @@ Widget _offerImage(
 }) {
   final inline = decodeDataUri(url);
   if (inline != null) {
+    // For a sized thumbnail, decode down to its on-screen pixels instead of the
+    // photo's full resolution (Play's "bitmap downscaling"). The hero image
+    // passes no width, so it decodes at native size as intended.
+    final dpr = MediaQuery.devicePixelRatioOf(context);
     return Image.memory(
       inline,
       width: width,
       height: height,
+      cacheWidth: width == null ? null : (width * dpr).round(),
+      cacheHeight: height == null ? null : (height * dpr).round(),
       fit: BoxFit.cover,
       semanticLabel: semanticLabel,
       errorBuilder: (context, _, _) =>

apps/app_seeds/lib/ui/peer_avatar.dart

@@ -34,7 +34,19 @@ class PeerAvatar extends StatelessWidget {
     if (pic.startsWith('data:')) {
       final bytes = decodeDataUri(pic);
       if (bytes != null) {
-        return CircleAvatar(radius: radius, backgroundImage: MemoryImage(bytes));
+        // Decode the photo down to the avatar's on-screen size (in physical
+        // pixels) instead of full resolution — the "bitmap downscaling" Play
+        // recommends. A tiny disc never needs a multi-megapixel decode.
+        final side = (radius * 2 * MediaQuery.devicePixelRatioOf(context))
+            .round();
+        return CircleAvatar(
+          radius: radius,
+          backgroundImage: ResizeImage(
+            MemoryImage(bytes),
+            width: side,
+            height: side,
+          ),
+        );
       }
     } else if (pic.startsWith(avatarGlyphPrefix)) {
       final glyph = avatarGlyphChar(pic.substring(avatarGlyphPrefix.length));

apps/app_seeds/lib/ui/photo_pick.dart

@@ -4,6 +4,7 @@ import 'package:flutter/material.dart';
 import 'package:image_picker/image_picker.dart';
 
 import '../i18n/strings.g.dart';
+import '../services/camera_availability.dart';
 
 /// Asks the user to take a photo or pick one from the gallery, then returns its
 /// bytes (or null if cancelled/unavailable). Camera failures — e.g. on desktop,
@@ -16,12 +17,15 @@ Future<Uint8List?> pickPhoto(BuildContext context) async {
       child: Column(
         mainAxisSize: MainAxisSize.min,
         children: [
-          ListTile(
-            key: const Key('photo.source.camera'),
-            leading: const Icon(Icons.photo_camera_outlined),
-            title: Text(t.photo.camera),
-            onTap: () => Navigator.of(sheetContext).pop(ImageSource.camera),
-          ),
+          // Only offer the camera when the device actually has one; camera-less
+          // devices (Chromebooks, Automotive, some TVs) fall back to gallery.
+          if (deviceHasCamera)
+            ListTile(
+              key: const Key('photo.source.camera'),
+              leading: const Icon(Icons.photo_camera_outlined),
+              title: Text(t.photo.camera),
+              onTap: () => Navigator.of(sheetContext).pop(ImageSource.camera),
+            ),
           ListTile(
             key: const Key('photo.source.gallery'),
             leading: const Icon(Icons.photo_library_outlined),
@@ -57,12 +61,15 @@ Future<List<Uint8List>> pickPhotos(BuildContext context) async {
       child: Column(
         mainAxisSize: MainAxisSize.min,
         children: [
-          ListTile(
-            key: const Key('photos.source.camera'),
-            leading: const Icon(Icons.photo_camera_outlined),
-            title: Text(t.photo.camera),
-            onTap: () => Navigator.of(sheetContext).pop(ImageSource.camera),
-          ),
+          // Only offer the camera when the device actually has one; camera-less
+          // devices (Chromebooks, Automotive, some TVs) fall back to gallery.
+          if (deviceHasCamera)
+            ListTile(
+              key: const Key('photos.source.camera'),
+              leading: const Icon(Icons.photo_camera_outlined),
+              title: Text(t.photo.camera),
+              onTap: () => Navigator.of(sheetContext).pop(ImageSource.camera),
+            ),
           ListTile(
             key: const Key('photos.source.gallery'),
             leading: const Icon(Icons.photo_library_outlined),

apps/app_seeds/lib/ui/qr_scan.dart

@@ -7,12 +7,17 @@ import 'package:zxing_barcode_scanner/zxing_barcode_scanner.dart';
 import '../data/species_repository.dart';
 import '../data/variety_repository.dart';
 import '../i18n/strings.g.dart';
+import '../services/camera_availability.dart';
 import '../services/seed_label_scan.dart';
 
 /// Whether this platform can open the camera scanner. Mobile-only for now
 /// (pure-ZXing platform views; no Google Play Services) — elsewhere the scan
-/// button simply isn't offered, same pattern as the OCR capture.
-bool get qrScanSupported => !kIsWeb && (Platform.isAndroid || Platform.isIOS);
+/// button simply isn't offered, same pattern as the OCR capture. On Android it
+/// also requires an actual camera, so camera-less devices (Chromebooks,
+/// Automotive, some TVs) don't get a scan button that can't open — see
+/// [deviceHasCamera].
+bool get qrScanSupported =>
+    !kIsWeb && ((Platform.isAndroid && deviceHasCamera) || Platform.isIOS);
 
 /// Opens the full-screen camera scanner and returns the first decoded QR
 /// payload, or null if the person backed out. (Ğ1nkgo's scanner pattern on

apps/app_seeds/lib/ui/quick_add_sheet.dart

@@ -199,6 +199,8 @@ class _MoreSection extends StatelessWidget {
             child: Image.memory(
               state.photoBytes!,
               height: 120,
+              cacheHeight:
+                  (120 * MediaQuery.devicePixelRatioOf(context)).round(),
               fit: BoxFit.cover,
             ),
           ),

apps/app_seeds/lib/ui/variety_detail_screen.dart

@@ -2244,10 +2244,16 @@ class _PhotoGalleryState extends State<_PhotoGallery> {
                 itemBuilder: (_, i) => GestureDetector(
                   key: Key('photo.thumb.$i'),
                   onTap: () => _openPhotoViewer(context, cubit, i),
+                  // Decode to the 140px thumbnail size (× dpr), not full photo
+                  // resolution — the full-res decode happens in the viewer.
                   child: Image.memory(
                     photos[i].bytes,
                     width: 140,
                     height: 140,
+                    cacheWidth:
+                        (140 * MediaQuery.devicePixelRatioOf(context)).round(),
+                    cacheHeight:
+                        (140 * MediaQuery.devicePixelRatioOf(context)).round(),
                     fit: BoxFit.cover,
                   ),
                 ),