feat: follow button

closes #22

lib/widgets/button_follow.dart

@@ -0,0 +1,69 @@
+import 'package:flutter/material.dart';
+import 'package:zap_stream_flutter/main.dart';
+import 'package:zap_stream_flutter/theme.dart';
+import 'package:zap_stream_flutter/widgets/button.dart';
+
+class FollowButton extends StatelessWidget {
+  final String pubkey;
+  final void Function()? onTap;
+  final void Function()? onFollow;
+  final void Function()? onUnfollow;
+
+  const FollowButton({
+    super.key,
+    required this.pubkey,
+    this.onTap,
+    this.onFollow,
+    this.onUnfollow,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    final signer = ndk.accounts.getLoggedAccount()?.signer;
+    if (signer == null || signer.getPublicKey() == pubkey) {
+      return SizedBox.shrink();
+    }
+
+    return FutureBuilder(
+      future: ndk.follows.getContactList(signer.getPublicKey()),
+      builder: (context, state) {
+        final follows = state.data?.contacts ?? [];
+        final isFollowing = follows.contains(pubkey);
+        return BasicButton(
+          Row(
+            mainAxisAlignment: MainAxisAlignment.center,
+            spacing: 4,
+            children: [
+              Icon(isFollowing ? Icons.person_remove : Icons.person_add, size: 16),
+              Text(
+                isFollowing ? "Unfollow" : "Follow",
+                style: TextStyle(fontWeight: FontWeight.bold),
+              ),
+            ],
+          ),
+          padding: EdgeInsets.symmetric(vertical: 4, horizontal: 12),
+          decoration: BoxDecoration(
+            borderRadius: DEFAULT_BR,
+            color: LAYER_2,
+          ),
+          onTap: () async {
+            if (onTap != null) {
+              onTap!();
+            }
+            if (isFollowing) {
+              await ndk.follows.broadcastRemoveContact(pubkey);
+              if (onUnfollow != null) {
+                onUnfollow!();
+              }
+            } else {
+              await ndk.follows.broadcastAddContact(pubkey);
+              if (onFollow != null) {
+                onFollow!();
+              }
+            }
+          },
+        );
+      },
+    );
+  }
+}

lib/widgets/chat_modal.dart

@@ -1,6 +1,7 @@
 import 'package:flutter/material.dart';
 import 'package:ndk/ndk.dart';
 import 'package:zap_stream_flutter/theme.dart';
+import 'package:zap_stream_flutter/widgets/button_follow.dart';
 import 'package:zap_stream_flutter/widgets/mute_button.dart';
 import 'package:zap_stream_flutter/widgets/nostr_text.dart';
 import 'package:zap_stream_flutter/widgets/profile.dart';
@@ -75,6 +76,12 @@ class _ChatModalWidget extends State<ChatModalWidget> {
             ],
           ),
           if (_showEmojiPicker) ReactionWidget(event: widget.event),
+          FollowButton(
+            pubkey: widget.event.pubKey,
+            onTap: () {
+              Navigator.pop(context);
+            },
+          ),
           MuteButton(
             pubkey: widget.event.pubKey,
             onTap: () {

lib/widgets/mute_button.dart

@@ -39,7 +39,10 @@ class MuteButton extends StatelessWidget {
             ),
           ),
           padding: EdgeInsets.symmetric(vertical: 4, horizontal: 12),
-          decoration: BoxDecoration(color: WARNING, borderRadius: DEFAULT_BR),
+          decoration: BoxDecoration(
+            color: isMuted ? LAYER_2 : WARNING,
+            borderRadius: DEFAULT_BR,
+          ),
           onTap: () async {
             if (onTap != null) {
               onTap!();

lib/widgets/stream_cards.dart

@@ -60,13 +60,18 @@ class StreamCardsWidget extends StatelessWidget {
       decoration: BoxDecoration(color: LAYER_2, borderRadius: DEFAULT_BR),
       child: Column(
         spacing: 8,
+        crossAxisAlignment: CrossAxisAlignment.start,
         children: [
           if (title?.isNotEmpty ?? false)
-            Text(
+            Center(
+              child: Text(
                 title!,
                 style: TextStyle(fontSize: 20, fontWeight: FontWeight.bold),
               ),
+            ),
           if (image?.isNotEmpty ?? false)
+            Center(
+              child:
                   link != null
                       ? GestureDetector(
                         onTap: () {
@@ -75,11 +80,14 @@ class StreamCardsWidget extends StatelessWidget {
                         child: CachedNetworkImage(
                           imageUrl: proxyImg(context, image!),
                           errorWidget:
-                        (_, _, _) =>
-                            SvgPicture.asset("assets/svg/logo.svg", height: 40),
+                              (_, _, _) => SvgPicture.asset(
+                                "assets/svg/logo.svg",
+                                height: 40,
+                              ),
                         ),
                       )
                       : CachedNetworkImage(imageUrl: proxyImg(context, image!)),
+            ),
           MarkdownBody(
             data: card.content,
             onTapLink: (text, href, title) {

lib/widgets/stream_info.dart

@@ -2,6 +2,7 @@ import 'package:flutter/material.dart';
 import 'package:intl/intl.dart';
 import 'package:zap_stream_flutter/theme.dart';
 import 'package:zap_stream_flutter/utils.dart';
+import 'package:zap_stream_flutter/widgets/button_follow.dart';
 import 'package:zap_stream_flutter/widgets/profile.dart';
 import 'package:zap_stream_flutter/widgets/stream_cards.dart';
 
@@ -23,6 +24,12 @@ class StreamInfoWidget extends StatelessWidget {
         crossAxisAlignment: CrossAxisAlignment.start,
         children: [
           ProfileWidget.pubkey(stream.info.host),
+          FollowButton(
+            pubkey: stream.info.host,
+            onTap: () {
+              Navigator.pop(context);
+            },
+          ),
           Text(
             stream.info.title ?? "",
             style: TextStyle(fontSize: 20, fontWeight: FontWeight.bold),