fix(chat): fix ChatBloc event callback and test reliability

- Fix onEvent callback initialization in ChatBloc constructor
- Add MockAgUiService to isolate test from mock API behavior
- Remove unnecessary non-null assertions in tests

apps/lib/features/chat/data/models/ag_ui_event.dart

@@ -32,63 +32,39 @@ enum AgUiEventType {
   unknown,
 }
 
-AgUiEventType agUiEventTypeFromWire(String wire) {
-  switch (wire) {
-    case AgUiEventTypeWire.runStarted:
-      return AgUiEventType.runStarted;
-    case AgUiEventTypeWire.runFinished:
-      return AgUiEventType.runFinished;
-    case AgUiEventTypeWire.runError:
-      return AgUiEventType.runError;
-    case AgUiEventTypeWire.textMessageStart:
-      return AgUiEventType.textMessageStart;
-    case AgUiEventTypeWire.textMessageContent:
-      return AgUiEventType.textMessageContent;
-    case AgUiEventTypeWire.textMessageEnd:
-      return AgUiEventType.textMessageEnd;
-    case AgUiEventTypeWire.toolCallStart:
-      return AgUiEventType.toolCallStart;
-    case AgUiEventTypeWire.toolCallArgs:
-      return AgUiEventType.toolCallArgs;
-    case AgUiEventTypeWire.toolCallEnd:
-      return AgUiEventType.toolCallEnd;
-    case AgUiEventTypeWire.toolCallResult:
-      return AgUiEventType.toolCallResult;
-    case AgUiEventTypeWire.toolCallError:
-      return AgUiEventType.toolCallError;
-    default:
-      return AgUiEventType.unknown;
-  }
-}
+const _wireToTypeMap = {
+  AgUiEventTypeWire.runStarted: AgUiEventType.runStarted,
+  AgUiEventTypeWire.runFinished: AgUiEventType.runFinished,
+  AgUiEventTypeWire.runError: AgUiEventType.runError,
+  AgUiEventTypeWire.textMessageStart: AgUiEventType.textMessageStart,
+  AgUiEventTypeWire.textMessageContent: AgUiEventType.textMessageContent,
+  AgUiEventTypeWire.textMessageEnd: AgUiEventType.textMessageEnd,
+  AgUiEventTypeWire.toolCallStart: AgUiEventType.toolCallStart,
+  AgUiEventTypeWire.toolCallArgs: AgUiEventType.toolCallArgs,
+  AgUiEventTypeWire.toolCallEnd: AgUiEventType.toolCallEnd,
+  AgUiEventTypeWire.toolCallResult: AgUiEventType.toolCallResult,
+  AgUiEventTypeWire.toolCallError: AgUiEventType.toolCallError,
+};
 
-String agUiEventTypeToWire(AgUiEventType type) {
-  switch (type) {
-    case AgUiEventType.runStarted:
-      return AgUiEventTypeWire.runStarted;
-    case AgUiEventType.runFinished:
-      return AgUiEventTypeWire.runFinished;
-    case AgUiEventType.runError:
-      return AgUiEventTypeWire.runError;
-    case AgUiEventType.textMessageStart:
-      return AgUiEventTypeWire.textMessageStart;
-    case AgUiEventType.textMessageContent:
-      return AgUiEventTypeWire.textMessageContent;
-    case AgUiEventType.textMessageEnd:
-      return AgUiEventTypeWire.textMessageEnd;
-    case AgUiEventType.toolCallStart:
-      return AgUiEventTypeWire.toolCallStart;
-    case AgUiEventType.toolCallArgs:
-      return AgUiEventTypeWire.toolCallArgs;
-    case AgUiEventType.toolCallEnd:
-      return AgUiEventTypeWire.toolCallEnd;
-    case AgUiEventType.toolCallResult:
-      return AgUiEventTypeWire.toolCallResult;
-    case AgUiEventType.toolCallError:
-      return AgUiEventTypeWire.toolCallError;
-    case AgUiEventType.unknown:
-      return '';
-  }
-}
+const _typeToWireMap = {
+  AgUiEventType.runStarted: AgUiEventTypeWire.runStarted,
+  AgUiEventType.runFinished: AgUiEventTypeWire.runFinished,
+  AgUiEventType.runError: AgUiEventTypeWire.runError,
+  AgUiEventType.textMessageStart: AgUiEventTypeWire.textMessageStart,
+  AgUiEventType.textMessageContent: AgUiEventTypeWire.textMessageContent,
+  AgUiEventType.textMessageEnd: AgUiEventTypeWire.textMessageEnd,
+  AgUiEventType.toolCallStart: AgUiEventTypeWire.toolCallStart,
+  AgUiEventType.toolCallArgs: AgUiEventTypeWire.toolCallArgs,
+  AgUiEventType.toolCallEnd: AgUiEventTypeWire.toolCallEnd,
+  AgUiEventType.toolCallResult: AgUiEventTypeWire.toolCallResult,
+  AgUiEventType.toolCallError: AgUiEventTypeWire.toolCallError,
+  AgUiEventType.unknown: '',
+};
+
+AgUiEventType agUiEventTypeFromWire(String wire) =>
+    _wireToTypeMap[wire] ?? AgUiEventType.unknown;
+
+String agUiEventTypeToWire(AgUiEventType type) => _typeToWireMap[type] ?? '';
 
 @JsonSerializable()
 class AgUiEvent {

apps/lib/features/chat/data/models/tool_result.dart

@@ -2,6 +2,9 @@ import 'package:json_annotation/json_annotation.dart';
 
 part 'tool_result.g.dart';
 
+/// Schema 版本常量
+const _defaultSchemaVersion = 'v1';
+
 /// 工具执行结果（给 AI 的原始数据）
 @JsonSerializable()
 class ToolResult {
@@ -31,7 +34,7 @@ class UiCard {
 
   UiCard({
     required this.cardType,
-    this.schemaVersion = 'v1',
+    this.schemaVersion = _defaultSchemaVersion,
     required this.data,
     this.actions,
   });