feat(profile): Material default avatar + square photo crop

Drop the DiceBear generated avatar (and dicebear_core/dicebear_styles/
flutter_svg): the default is again a Material coloured-initial disc from
the pubkey. Picking a photo now goes through a square crop step
(crop_your_image — pure Flutter, all platforms incl. desktop, Apache-2.0,
only pulls the image package we already had) before the 24 KB thumbnail.

apps/app_seeds/lib/ui/avatar_edit.dart

@@ -2,14 +2,16 @@ import 'package:flutter/material.dart';
 
 import '../i18n/strings.g.dart';
 import '../services/offer_thumbnail.dart' show offerThumbnailDataUri;
+import 'photo_crop.dart';
 import 'photo_pick.dart';
 import 'theme.dart';
 
-/// Lets the user choose a profile avatar: take/pick a photo (shrunk to a tiny
+/// Lets the user choose a profile avatar: take/pick a photo, square-crop it, and
-/// inline thumbnail) or remove it. With no photo, a generated avatar is used.
+/// keep it as a tiny inline thumbnail — or remove it. With no photo, the
+/// coloured-initial disc is used.
 ///
 /// Returns the new avatar value (a `data:` photo thumbnail), an empty string to
-/// clear it (falls back to the generated avatar), or null when cancelled.
+/// clear it (falls back to the coloured-initial disc), or null when cancelled.
 Future<String?> showAvatarPicker(
   BuildContext context, {
   required String current,
@@ -37,11 +39,11 @@ Future<String?> showAvatarPicker(
                 title: Text(t.avatar.fromPhoto),
                 onTap: () async {
                   final bytes = await pickPhoto(sheetContext);
-                  if (bytes == null) return;
+                  if (bytes == null || !sheetContext.mounted) return;
-                  final uri = offerThumbnailDataUri(bytes, maxBytes: 24000);
+                  final cropped = await cropToSquare(sheetContext, bytes);
-                  if (sheetContext.mounted) {
+                  if (cropped == null || !sheetContext.mounted) return;
+                  final uri = offerThumbnailDataUri(cropped, maxBytes: 24000);
                   Navigator.of(sheetContext).pop(uri ?? '');
-                  }
                 },
               ),
               if (current.isNotEmpty) ...[

apps/app_seeds/lib/ui/peer_avatar.dart

@@ -1,7 +1,4 @@
-import 'package:dicebear_core/dicebear_core.dart' show Avatar, Style;
-import 'package:dicebear_styles/thumbs.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_svg/flutter_svg.dart';
 
 import '../services/offer_thumbnail.dart' show decodeDataUri;
 import '../services/profile_cache.dart';
@@ -9,10 +6,11 @@ import 'avatar.dart';
 import 'seed_glyph.dart';
 
 /// A small round avatar for a person. When they've set an avatar ([picture] — a
-/// `data:` photo thumbnail or a `tane:seed:<glyph>` illustration) it's shown;
+/// `data:` photo thumbnail, or a legacy `tane:seed:<glyph>` illustration) it's
-/// otherwise it falls back to a [GeneratedAvatar] drawn deterministically from
+/// shown; otherwise it falls back to a standard disc coloured deterministically
-/// their [pubkey]. Same pubkey → same picture on every device, so a person
+/// from their [pubkey], carrying the first letter of their [name] (a person icon
-/// stays visually recognizable without sharing anything.
+/// when unknown). Same pubkey → same colour on every device, so a person stays
+/// visually recognizable without sharing anything.
 class PeerAvatar extends StatelessWidget {
   const PeerAvatar({
     required this.pubkey,
@@ -25,7 +23,7 @@ class PeerAvatar extends StatelessWidget {
   final String pubkey;
   final String? name;
 
-  /// The person's chosen avatar value; null/empty → the [GeneratedAvatar].
+  /// The person's chosen avatar value; null/empty → the coloured-initial disc.
   final String? picture;
   final double radius;
 
@@ -49,61 +47,35 @@ class PeerAvatar extends StatelessWidget {
       }
     }
 
-    return GeneratedAvatar(pubkey: pubkey, name: name, radius: radius);
+    final letter = _initial(name);
-  }
+    return CircleAvatar(
-}
+      radius: radius,
-
+      backgroundColor: peerAvatarColor(pubkey),
-/// The `thumbs` DiceBear style, parsed once — [Style.parse] validates the style
+      child: letter == null
-/// definition against its schema, which is not free to repeat per build.
+          ? Icon(Icons.person_outline, size: radius, color: Colors.white)
-final _thumbsStyle = Style.parse(thumbs);
+          : Text(
-
+              letter,
-/// Rendered-SVG memo keyed by pubkey, so a person's avatar is generated once and
+              style: TextStyle(
-/// reused across every rebuild and list row rather than re-rendered each time.
+                color: Colors.white,
-final _svgCache = <String, String>{};
+                fontSize: radius,
-
+                fontWeight: FontWeight.w600,
-/// Strips the `<metadata>` block (the style's CC0 licence notice) that
-/// flutter_svg cannot parse and logs a warning for; CC0 requires no attribution
-/// in the rendered image, and the licence still ships with the package source.
-final _metadataElement = RegExp(r'<metadata\b[^>]*>.*?</metadata>', dotAll: true);
-
-String _renderThumbs(String pubkey) =>
-    Avatar(_thumbsStyle, {'seed': pubkey}).svg.replaceAll(_metadataElement, '');
-
-/// The deterministic default avatar for a person with no chosen [picture]: a
-/// friendly DiceBear "thumbs" face (CC0) seeded from their [pubkey], so the same
-/// key yields the same face on every device with nothing shared. Rendered as an
-/// SVG (no network, no assets). Exposes [pubkey] so call sites/tests can find it.
-class GeneratedAvatar extends StatelessWidget {
-  const GeneratedAvatar({
-    required this.pubkey,
-    this.name,
-    this.radius = 14,
-    super.key,
-  });
-
-  final String pubkey;
-  final String? name;
-  final double radius;
-
-  @override
-  Widget build(BuildContext context) {
-    final svg = _svgCache[pubkey] ??= _renderThumbs(pubkey);
-    return Semantics(
-      label: name,
-      image: true,
-      child: ClipOval(
-        child: SizedBox.square(
-          dimension: radius * 2,
-          child: SvgPicture.string(svg, fit: BoxFit.cover),
               ),
             ),
     );
   }
+
+  static String? _initial(String? name) {
+    if (name == null) return null;
+    final trimmed = name.trim();
+    if (trimmed.isEmpty) return null;
+    // characters.first handles emoji/combining marks safely.
+    return trimmed.characters.first.toUpperCase();
+  }
 }
 
 /// A [PeerAvatar] that looks the person's published avatar up from the
-/// [ProfileCache] (their kind:0 `picture`), falling back to the generated
+/// [ProfileCache] (their kind:0 `picture`), falling back to the coloured-initial
-/// pattern while it loads or when none is cached / no cache is available. Use at
+/// disc while it loads or when none is cached / no cache is available. Use at
 /// list/row sites (one avatar each); for many avatars of the same few people
 /// (chat bubbles) resolve the picture once into state instead.
 class CachedAvatar extends StatelessWidget {

apps/app_seeds/lib/ui/photo_crop.dart

@@ -0,0 +1,87 @@
+import 'dart:typed_data';
+
+import 'package:crop_your_image/crop_your_image.dart';
+import 'package:flutter/material.dart';
+
+import 'theme.dart';
+
+/// Lets the user square-crop the picked [bytes] before it's saved as an avatar.
+/// Returns the cropped image bytes, or null if cancelled. Pure Flutter (works on
+/// every platform, desktop included) — no native cropper, no plaintext on disk.
+Future<Uint8List?> cropToSquare(BuildContext context, Uint8List bytes) {
+  return Navigator.of(context).push<Uint8List>(
+    MaterialPageRoute(
+      fullscreenDialog: true,
+      builder: (context) => _CropPage(bytes: bytes),
+    ),
+  );
+}
+
+class _CropPage extends StatefulWidget {
+  const _CropPage({required this.bytes});
+
+  final Uint8List bytes;
+
+  @override
+  State<_CropPage> createState() => _CropPageState();
+}
+
+class _CropPageState extends State<_CropPage> {
+  final _controller = CropController();
+  var _cropping = false;
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      backgroundColor: Colors.black,
+      appBar: AppBar(
+        backgroundColor: Colors.black,
+        foregroundColor: Colors.white,
+        leading: IconButton(
+          key: const Key('crop.cancel'),
+          icon: const Icon(Icons.close),
+          onPressed: () => Navigator.of(context).pop(),
+        ),
+        actions: [
+          if (_cropping)
+            const Padding(
+              padding: EdgeInsets.all(14),
+              child: SizedBox(
+                width: 20,
+                height: 20,
+                child: CircularProgressIndicator(strokeWidth: 2),
+              ),
+            )
+          else
+            IconButton(
+              key: const Key('crop.confirm'),
+              icon: const Icon(Icons.check),
+              onPressed: () {
+                setState(() => _cropping = true);
+                _controller.crop();
+              },
+            ),
+        ],
+      ),
+      body: Crop(
+        image: widget.bytes,
+        controller: _controller,
+        aspectRatio: 1,
+        withCircleUi: true,
+        baseColor: Colors.black,
+        maskColor: Colors.black.withValues(alpha: 0.6),
+        cornerDotBuilder: (size, edgeAlignment) =>
+            const DotControl(color: seedGreen),
+        onCropped: (result) {
+          if (!mounted) return;
+          switch (result) {
+            case CropSuccess(:final croppedImage):
+              Navigator.of(context).pop(croppedImage);
+            case CropFailure():
+              setState(() => _cropping = false);
+          }
+        },
+      ),
+    );
+  }
+}

apps/app_seeds/pubspec.yaml

@@ -78,9 +78,7 @@ dependencies:
   # while the app is foregrounded. Mobile/Linux/macOS only; a no-op on web and
   # Windows. Foreground-only by design — background/push is a later concern.
   flutter_local_notifications: ^18.0.1
-  dicebear_core: ^10.3.0
+  crop_your_image: ^2.0.0
-  dicebear_styles: ^10.2.0
-  flutter_svg: ^2.3.0
 
 dev_dependencies:
   flutter_test:

apps/app_seeds/test/ui/chat_message_list_test.dart

@@ -124,14 +124,14 @@ void main() {
     await tester.pumpWidget(host(cubit));
     await tester.pump();
 
-    // Both sides carry an avatar, each generated from its own pubkey —
+    // Both sides carry an avatar, and the two people are different colours —
     // so you can tell who said what at a glance.
     expect(find.byType(PeerAvatar), findsNWidgets(2));
-    final generated = tester
+    final discs = tester
-        .widgetList<GeneratedAvatar>(find.byType(GeneratedAvatar))
+        .widgetList<CircleAvatar>(find.byType(CircleAvatar))
         .toList();
-    expect(generated, hasLength(2));
+    expect(discs, hasLength(2));
-    expect(generated.first.pubkey, isNot(generated.last.pubkey));
+    expect(discs.first.backgroundColor, isNot(discs.last.backgroundColor));
   });
 
   testWidgets('a new message lands in view at the bottom, not below the fold', (

apps/app_seeds/test/ui/peer_avatar_test.dart

@@ -36,19 +36,17 @@ void main() {
       home: Scaffold(body: Center(child: child)),
     );
 
-    testWidgets('falls back to a generated avatar keyed by pubkey', (
+    testWidgets('shows the name initial when known', (tester) async {
-      tester,
-    ) async {
       await tester.pumpWidget(host(PeerAvatar(pubkey: 'aa', name: 'rosa')));
-      final generated =
+      expect(find.text('R'), findsOneWidget); // uppercased first letter
-          tester.widget<GeneratedAvatar>(find.byType(GeneratedAvatar));
-      expect(generated.pubkey, 'aa'); // pubkey, not name → stable across renames
-      expect(find.byType(Text), findsNothing);
     });
 
-    testWidgets('generates it even when the name is unknown', (tester) async {
+    testWidgets('falls back to a person icon when the name is unknown', (
+      tester,
+    ) async {
       await tester.pumpWidget(host(const PeerAvatar(pubkey: 'aa')));
-      expect(find.byType(GeneratedAvatar), findsOneWidget);
+      expect(find.byIcon(Icons.person_outline), findsOneWidget);
+      expect(find.byType(Text), findsNothing);
     });
 
     testWidgets('renders a seed illustration when the avatar is a token', (
@@ -75,19 +73,19 @@ void main() {
       expect(find.byType(SeedGlyph), findsOneWidget);
     });
 
-    testWidgets('falls back to the generated avatar when nothing is cached', (
+    testWidgets('falls back to the initial when nothing is cached', (
       tester,
     ) async {
       final cache = ProfileCache(InMemorySecretStore());
       await tester.pumpWidget(host(
           CachedAvatar(pubkey: 'peer2', name: 'Bea', cache: cache)));
       await tester.pumpAndSettle();
-      expect(find.byType(GeneratedAvatar), findsOneWidget);
+      expect(find.text('B'), findsOneWidget);
     });
 
-    testWidgets('no cache → the generated avatar', (tester) async {
+    testWidgets('no cache → the coloured-initial disc', (tester) async {
       await tester.pumpWidget(host(const CachedAvatar(pubkey: 'x', name: 'Bea')));
-      expect(find.byType(GeneratedAvatar), findsOneWidget);
+      expect(find.text('B'), findsOneWidget);
     });
   });
 }

apps/app_seeds/test/ui/photo_crop_test.dart

@@ -0,0 +1,48 @@
+import 'dart:typed_data';
+
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:image/image.dart' as img;
+import 'package:tane/ui/photo_crop.dart';
+
+void main() {
+  // A small but real PNG the cropper can decode.
+  final bytes = Uint8List.fromList(
+    img.encodePng(img.Image(width: 32, height: 32)),
+  );
+
+  testWidgets('cropToSquare shows a cancel/confirm UI and cancel returns null', (
+    tester,
+  ) async {
+    Uint8List? result;
+    var returned = false;
+    await tester.pumpWidget(MaterialApp(
+      home: Builder(
+        builder: (context) => Scaffold(
+          body: Center(
+            child: ElevatedButton(
+              onPressed: () async {
+                result = await cropToSquare(context, bytes);
+                returned = true;
+              },
+              child: const Text('open'),
+            ),
+          ),
+        ),
+      ),
+    ));
+
+    await tester.tap(find.text('open'));
+    await tester.pump(); // push the crop route
+    await tester.pump(const Duration(milliseconds: 100));
+
+    expect(find.byKey(const Key('crop.confirm')), findsOneWidget);
+    expect(find.byKey(const Key('crop.cancel')), findsOneWidget);
+
+    await tester.tap(find.byKey(const Key('crop.cancel')));
+    await tester.pump(); // pop the crop route
+
+    expect(returned, isTrue);
+    expect(result, isNull); // cancelling yields no image
+  });
+}

pubspec.lock

@@ -241,6 +241,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.15.1"
+  crop_your_image:
+    dependency: transitive
+    description:
+      name: crop_your_image
+      sha256: "14c8977b11a009dc5e73e0f6522970f93363e38183f1b2ffefe1676dc9c3f49d"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.0.0"
   cross_file:
     dependency: transitive
     description:
@@ -297,30 +305,6 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "0.7.14"
-  dicebear_core:
-    dependency: transitive
-    description:
-      name: dicebear_core
-      sha256: "7a38725ed8895feeeb6d34a6a0946322a03649077fa49f9a711530e035fb53f2"
-      url: "https://pub.dev"
-    source: hosted
-    version: "10.3.0"
-  dicebear_schema:
-    dependency: transitive
-    description:
-      name: dicebear_schema
-      sha256: dfbaa477e4e7ed1500ae8f0263ecf7db3081c492489b817a401a52e21e0ace9c
-      url: "https://pub.dev"
-    source: hosted
-    version: "1.3.0"
-  dicebear_styles:
-    dependency: transitive
-    description:
-      name: dicebear_styles
-      sha256: "4761fc26da7eb12b5b499be4efbd7cadc9186e301095199bbf424a3150bcd866"
-      url: "https://pub.dev"
-    source: hosted
-    version: "10.2.0"
   drift:
     dependency: transitive
     description:
@@ -552,14 +536,6 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "3.1.2"
-  flutter_svg:
-    dependency: transitive
-    description:
-      name: flutter_svg
-      sha256: "35882981abcbfb8c15b286f0cd690ff25bac12d95eff3e25ee207f37d4c42e7f"
-      url: "https://pub.dev"
-    source: hosted
-    version: "2.3.0"
   flutter_tesseract_ocr:
     dependency: transitive
     description:
@@ -836,14 +812,6 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "4.12.0"
-  json_schema:
-    dependency: transitive
-    description:
-      name: json_schema
-      sha256: f37d9c3fdfe8c9aae55fdfd5af815d24ce63c3a0f6a2c1f0982c30f43643fa1a
-      url: "https://pub.dev"
-    source: hosted
-    version: "5.2.2"
   leak_tracker:
     dependency: transitive
     description:
@@ -1156,14 +1124,6 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "3.0.2"
-  quiver:
-    dependency: transitive
-    description:
-      name: quiver
-      sha256: ea0b925899e64ecdfbf9c7becb60d5b50e706ade44a85b2363be2a22d88117d2
-      url: "https://pub.dev"
-    source: hosted
-    version: "3.2.2"
   recase:
     dependency: transitive
     description:
@@ -1180,14 +1140,6 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "0.6.0"
-  rfc_6901:
-    dependency: transitive
-    description:
-      name: rfc_6901
-      sha256: "6a43b1858dca2febaf93e15639aa6b0c49ccdfd7647775f15a499f872b018154"
-      url: "https://pub.dev"
-    source: hosted
-    version: "0.2.1"
   serial_csv:
     dependency: transitive
     description:
@@ -1409,14 +1361,6 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.3.1"
-  uri:
-    dependency: transitive
-    description:
-      name: uri
-      sha256: "889eea21e953187c6099802b7b4cf5219ba8f3518f604a1033064d45b1b8268a"
-      url: "https://pub.dev"
-    source: hosted
-    version: "1.0.0"
   url_launcher:
     dependency: transitive
     description:
@@ -1489,30 +1433,6 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "4.5.3"
-  vector_graphics:
-    dependency: transitive
-    description:
-      name: vector_graphics
-      sha256: "2306c03da2ba81724afeb589c351ebbc0aa7d86005925be8f8735856dbe5e42d"
-      url: "https://pub.dev"
-    source: hosted
-    version: "1.2.2"
-  vector_graphics_codec:
-    dependency: transitive
-    description:
-      name: vector_graphics_codec
-      sha256: "99fd9fbd34d9f9a32efd7b6a6aae14125d8237b10403b422a6a6dfeac2806146"
-      url: "https://pub.dev"
-    source: hosted
-    version: "1.1.13"
-  vector_graphics_compiler:
-    dependency: transitive
-    description:
-      name: vector_graphics_compiler
-      sha256: "142a9146f447d15b10bdc00e21d5f4d83e5b32bb5f8f8f5a04c75311344923a3"
-      url: "https://pub.dev"
-    source: hosted
-    version: "1.2.6"
   vector_math:
     dependency: transitive
     description: