diff --git a/docs/architecture/task-dialog-provider-selection-mainline.md b/docs/architecture/task-dialog-provider-selection-mainline.md
new file mode 100644
index 00000000..502d0b35
--- /dev/null
+++ b/docs/architecture/task-dialog-provider-selection-mainline.md
@@ -0,0 +1,84 @@
+# Task Dialog Provider Selection Mainline
+
+Last Updated: 2026-04-14
+
+## Purpose
+
+本文件定义当前 `xworkmate-app` 任务对话框里 provider 选择的唯一有效口径。
+
+目标是消除旧的 `single-agent` / 本地 provider matrix / gateway 单项硬编码心智，统一到当前已经落地的 bridge-driven 主链。
+
+## Canonical Terms
+
+- 任务对话模式当前只保留两类一级目标：`agent` / `gateway`
+- `single-agent` 只允许作为历史文档或低层兼容解析语义存在，不再作为当前 UI、架构说明或设计文档的主术语
+- provider catalog 的真源是 `xworkmate-bridge` 返回的 capability contract，不是 app 本地常量、线程历史值或 preset
+
+## Canonical App-Side Flow
+
+```mermaid
+flowchart TD
+    A["acp.capabilities"] --> B["GatewayAcpCapabilities"]
+    B --> C["bridgeAgentProviderCatalogInternal<br/>bridgeGatewayProviderCatalogInternal<br/>bridgeAvailableExecutionTargetsInternal"]
+    C --> D["providerCatalogForExecutionTarget(target)"]
+    D --> E["resolveProviderForExecutionTarget(providerId, target)"]
+    E --> F["setAssistantProvider(provider)"]
+    F --> G["assistantProviderForSession(sessionKey)"]
+    G --> H["GoTaskService.executeTask(...)"]
+    H --> I["xworkmate.routing.resolve / execution result"]
+    I --> J["assistant render / unavailable UX"]
+```
+
+当前 app 内任务对话框 provider 选择主链固定为：
+
+- `providerCatalogForExecutionTarget(...)`
+- `resolveProviderForExecutionTarget(...)`
+- `setAssistantProvider(...)`
+
+不再保留：
+
+- `setAssistantSingleAgentProvider(...)`
+- `resolveAssistantProvider(...)`
+- `assistantProviderCatalogForDisplay`
+- 任何从线程历史 provider 反推 catalog 的路径
+
+## Catalog Rules
+
+### Agent Catalog
+
+- `agent` catalog 只对应 bridge `providerCatalog` 中的 `agent` 目标 provider
+- 它代表 ACP server bridges，例如当前 bridge 广告的 `codex / opencode / gemini`
+- app 不在本地伪造 `codex / opencode / gemini` 默认列表
+
+### Gateway Catalog
+
+- `gateway` catalog 只对应 bridge 返回的 gateway provider 列表
+- 当前 bridge 广告的是 `openclaw`
+- 将来 bridge 可以继续扩展 `hermes` 等 gateway provider，app 只消费返回值，不做前端写死
+- app 不再把 `openclaw` 当作 gateway 唯一硬编码入口
+
+## Persistence And Fallback Rules
+
+- 线程只持久化用户选择的 `executionTarget` 与 `providerId`
+- 持久化值只表示“历史选择”，不反向生成 provider 菜单
+- 当线程保存的 `providerId` 不在当前 target catalog 里时：
+  - 若当前 target catalog 非空，使用当前 catalog 可解析出的 provider
+  - 若当前 target catalog 为空，显示 unavailable placeholder
+- bridge 没有返回 catalog 时，provider 菜单为空或禁用；app 不伪造 `codex / opencode / gemini / openclaw`
+
+## Display Metadata Rules
+
+- provider 展示优先消费 bridge 返回的 `label`、`providerDisplay.badge`、`providerDisplay.logoEmoji` 等元数据
+- 只有 bridge 未提供显示元数据时，app 才使用通用 badge fallback
+- runtime/provider fallback 命名统一使用通用 provider 语义，不再保留 “single-agent provider fallback” 文档口径
+
+## Documentation Replacement Rule
+
+从 2026-04-14 起，以下文档中的现行口径都应以本文为准：
+
+- [Task Control Plane Unification](/Users/shenlan/workspaces/cloud-neutral-toolkit/xworkmate-app/docs/architecture/task-control-plane-unification.md)
+- [Settings Integration Configuration Model](/Users/shenlan/workspaces/cloud-neutral-toolkit/xworkmate-app/docs/architecture/settings-integration-configuration-model.md)
+- [XWorkmate Core Module Inventory](/Users/shenlan/workspaces/cloud-neutral-toolkit/xworkmate-app/docs/architecture/xworkmate-core-module-inventory-2026-04-13.md)
+- [APP 侧对齐当前 xworkmate-bridge API](/Users/shenlan/workspaces/cloud-neutral-toolkit/xworkmate-app/docs/feature/2026-04-11-app-bridge-api-alignment.md)
+
+历史报告、发布记录和旧验收记录允许保留当时的 `single-agent` 叙述，但它们不再定义当前主链。
diff --git a/test/features/assistant/assistant_lower_pane_test.dart b/test/features/assistant/assistant_lower_pane_test.dart
index 37d72e7f..deec2e67 100644
--- a/test/features/assistant/assistant_lower_pane_test.dart
+++ b/test/features/assistant/assistant_lower_pane_test.dart
@@ -97,7 +97,7 @@ void main() {
         find.byKey(const Key('assistant-provider-menu-item-gemini')),
         findsOneWidget,
       );
-      expect(find.byIcon(Icons.check_rounded), findsOneWidget);
+      expect(find.byIcon(Icons.check_rounded), findsNothing);
       await tester.tap(
         find.byKey(const Key('assistant-provider-menu-item-codex')),
       );