Add app source and tests

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

lib/Peach/see/kafka/ViewKafka.dart

@@ -0,0 +1,94 @@
+import '../../about/internal/application/ServerProfile.dart';
+import '../parent/ParentViewModel.dart';
+import 'ConnectKafka.dart';
+
+class ViewKafka extends ParentViewModel {
+  ConnectKafka connection;
+
+  ViewKafka(super.context, this.connection);
+
+  /// Looks for the Kafka CLI tools on PATH and in the usual install dirs.
+  void detectKafka(ServerProfile server) async {
+    if (!await canReach(server, () => detectKafka(server))) return;
+    try {
+      final status = await getDataManager().kafkaDetect(server);
+      connection.onKafkaDetected(status);
+    } catch (error) {
+      connection.onDetectFailed(error.toString());
+    }
+  }
+
+  /// Reads topics, consumer groups and cluster health in one pass. They're
+  /// three separate CLI invocations, so this is where they're sequenced.
+  void scan(
+    ServerProfile server, {
+    required String binDir,
+    required String suffix,
+    required String bootstrap,
+    required bool includeInternal,
+  }) async {
+    try {
+      final topics = await getDataManager().kafkaTopics(
+        server,
+        binDir: binDir,
+        suffix: suffix,
+        bootstrap: bootstrap,
+        includeInternal: includeInternal,
+      );
+      final groups = await getDataManager().kafkaGroups(
+        server,
+        binDir: binDir,
+        suffix: suffix,
+        bootstrap: bootstrap,
+      );
+      final cluster = await getDataManager().kafkaCluster(
+        server,
+        binDir: binDir,
+        suffix: suffix,
+        bootstrap: bootstrap,
+      );
+
+      connection.onScanned(
+        KafkaScan(topics: topics, groups: groups, cluster: cluster),
+      );
+    } catch (error) {
+      connection.onScanFailed(error.toString());
+    }
+  }
+
+  /// Runs `kafka-broker-api-versions` so the user can see exactly what the
+  /// broker says when a scan comes back empty.
+  void probeBroker(
+    ServerProfile server, {
+    required String binDir,
+    required String suffix,
+    required String bootstrap,
+  }) async {
+    showLoading("Probing $bootstrap …");
+    try {
+      final output = await getDataManager().kafkaTest(
+        server,
+        binDir: binDir,
+        suffix: suffix,
+        bootstrap: bootstrap,
+      );
+      closeLoading();
+      connection.onProbeOutput(
+        'kafka-broker-api-versions · $bootstrap',
+        output.isEmpty ? '(no output — broker unreachable?)' : output,
+      );
+    } catch (error) {
+      handleError(
+        error,
+        () => probeBroker(
+          server,
+          binDir: binDir,
+          suffix: suffix,
+          bootstrap: bootstrap,
+        ),
+        () {},
+        "Retry",
+      );
+    }
+  }
+}