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.

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: