feat(send): animated hash-bag on the "Transaction Sent" screen

Replace the static success illustration with HashBagSuccessAnimation: the money
sack sits at the bottom and #/$/₿ glyphs erupt from its mouth, rising and fading
on a loop. Glyphs are PNG assets (the app bundles no font with a ₿ glyph).

InfoPage gains an overridable buildIllustration() hook (default unchanged:
static HashImageWidget); only TransactionSuccessPage overrides it, so every
other InfoPage is untouched.

NOTE: written without a local Flutter build (Dart pub can't resolve here) —
verify on the next CI/device build. Self-contained and revertible; the static
hash_bag.png remains the fallback via imageLightPath/imageDarkPath.

lib/src/screens/Info_page.dart

@@ -21,6 +21,12 @@ abstract class InfoPage extends BasePage {
   Key? get buttonKey;
   void Function(BuildContext) get onPressed;
 
+  /// The illustration shown at the top of the page. Defaults to the static
+  /// image at [imageLightPath]/[imageDarkPath]; subclasses can override to
+  /// supply an animated widget instead.
+  Widget buildIllustration(BuildContext context, String image) =>
+      HashImageWidget(imageUrl: image);
+
   @override
   bool get gradientBackground => true;
 
@@ -56,7 +62,7 @@ abstract class InfoPage extends BasePage {
                   ),
                   child: AspectRatio(
                     aspectRatio: 0.9,
-                    child: HashImageWidget(imageUrl: image),
+                    child: buildIllustration(context, image),
                   ),
                 ),
               ),

lib/src/screens/send/transaction_success_info_page.dart

@@ -1,5 +1,6 @@
 import 'package:hash_wallet/generated/i18n.dart';
 import 'package:hash_wallet/src/screens/Info_page.dart';
+import 'package:hash_wallet/src/widgets/hash_bag_success_animation.dart';
 import 'package:flutter/cupertino.dart';
 
 class TransactionSuccessPage extends InfoPage {
@@ -11,6 +12,10 @@ class TransactionSuccessPage extends InfoPage {
 
   final String content;
 
+  @override
+  Widget buildIllustration(BuildContext context, String image) =>
+      const HashBagSuccessAnimation();
+
   @override
   bool get onWillPop => false;
 

lib/src/widgets/hash_bag_success_animation.dart

@@ -0,0 +1,124 @@
+import 'package:flutter/material.dart';
+
+/// "Transaction sent" celebration: the Hash Bags money sack sits at the bottom
+/// and money glyphs (#, $, ₿) erupt from its mouth, rising and fading on a loop.
+///
+/// The glyphs are image assets (not text) because the app doesn't bundle a font
+/// containing a bitcoin glyph — rendering them as PNGs keeps them consistent
+/// across platforms.
+class HashBagSuccessAnimation extends StatefulWidget {
+  const HashBagSuccessAnimation({super.key});
+
+  @override
+  State<HashBagSuccessAnimation> createState() => _HashBagSuccessAnimationState();
+}
+
+class _Particle {
+  final String asset;
+  final double dx; // horizontal fan, fraction of width
+  final double phase; // stagger, 0..1
+  final double size; // fraction of width
+  const _Particle(this.asset, this.dx, this.phase, this.size);
+}
+
+class _HashBagSuccessAnimationState extends State<HashBagSuccessAnimation>
+    with SingleTickerProviderStateMixin {
+  late final AnimationController _controller;
+
+  static const String _hash = 'assets/images/hashbag_sym_hash.png';
+  static const String _dollar = 'assets/images/hashbag_sym_dollar.png';
+  static const String _btc = 'assets/images/hashbag_sym_btc.png';
+
+  static const List<_Particle> _particles = <_Particle>[
+    _Particle(_btc, 0.00, 0.00, 0.20),
+    _Particle(_hash, -0.18, 0.13, 0.16),
+    _Particle(_dollar, 0.19, 0.24, 0.16),
+    _Particle(_hash, 0.11, 0.40, 0.12),
+    _Particle(_dollar, -0.13, 0.54, 0.11),
+    _Particle(_btc, 0.06, 0.68, 0.12),
+    _Particle(_hash, -0.07, 0.83, 0.10),
+  ];
+
+  @override
+  void initState() {
+    super.initState();
+    _controller = AnimationController(
+      vsync: this,
+      duration: const Duration(milliseconds: 2800),
+    )..repeat();
+  }
+
+  @override
+  void dispose() {
+    _controller.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return LayoutBuilder(
+      builder: (BuildContext context, BoxConstraints constraints) {
+        final double w = constraints.maxWidth;
+        final double h = constraints.maxHeight;
+        // Sack anchored at the bottom (~62% of the height); mouth ≈ its top.
+        final double bagH = h * 0.62;
+        final double bagW = bagH * 0.825; // hash_bag_base.png aspect (w/h)
+        final double bagLeft = (w - bagW) / 2;
+        final double bagTop = h - bagH;
+        final double mouthX = w / 2;
+        final double mouthY = bagTop + bagH * 0.06;
+
+        return AnimatedBuilder(
+          animation: _controller,
+          builder: (BuildContext context, Widget? _) {
+            final List<Widget> children = <Widget>[
+              Positioned(
+                left: bagLeft,
+                top: bagTop,
+                width: bagW,
+                height: bagH,
+                child: Image.asset(
+                  'assets/images/hash_bag_base.png',
+                  fit: BoxFit.contain,
+                ),
+              ),
+            ];
+
+            for (final _Particle p in _particles) {
+              final double t = (_controller.value + p.phase) % 1.0;
+              final double sz = w * p.size;
+              final double rise = h * 0.52 * t;
+              final double spread = w * p.dx * (0.35 + t);
+              final double x = mouthX + spread - sz / 2;
+              final double y = mouthY - rise - sz / 2;
+              final double opacity = (t < 0.15
+                      ? t / 0.15
+                      : (t > 0.78 ? (1.0 - t) / 0.22 : 1.0))
+                  .clamp(0.0, 1.0)
+                  .toDouble();
+              final double scale = 0.55 + 0.45 * (t < 0.3 ? t / 0.3 : 1.0);
+
+              children.add(
+                Positioned(
+                  left: x,
+                  top: y,
+                  width: sz,
+                  height: sz,
+                  child: Opacity(
+                    opacity: opacity,
+                    child: Transform.scale(
+                      scale: scale,
+                      child: Image.asset(p.asset, fit: BoxFit.contain),
+                    ),
+                  ),
+                ),
+              );
+            }
+
+            return Stack(clipBehavior: Clip.none, children: children);
+          },
+        );
+      },
+    );
+  }
+}