feat: 饮食记录逻辑重构 + 通知管理分隔线修复 + 多页面 UI 调整

- 饮食: 新增 DietCommentaryPolicy + diet_record_logic, 饮食记录逻辑抽取复用
- 通知管理: 分隔线改为仿通知中心样式, 跳过图标区域只留文字下方
- 侧边栏: 对话记录操作栏浮层修复 + 常用功能间距收紧
- 智能体: 欢迎卡片去 400ms 延迟 + 胶囊去阴影
- 后端: AI 会话仓库新增方法 + 饮食评论策略 + 健康记录规则调整
- 其他: api_client IP 适配 + 多页面 UI 微调 + 新增测试

backend/tests/Health.Tests/application_service_tests.cs

@@ -223,6 +223,7 @@ public sealed class ApplicationServiceTests
         public Task<IReadOnlyList<ConversationMessage>> GetRecentMessagesAsync(Guid conversationId, int limit, CancellationToken ct) => Task.FromResult<IReadOnlyList<ConversationMessage>>([]);
         public Task AddConversationAsync(Conversation value, CancellationToken ct) => Task.CompletedTask;
         public Task AddMessageAsync(ConversationMessage message, CancellationToken ct) => Task.CompletedTask;
+        public Task<int> DeleteLegacyDietCommentaryArtifactsAsync(Guid userId, string promptPrefix, CancellationToken ct) => Task.FromResult(0);
         public void Delete(Conversation value) { }
         public Task SaveChangesAsync(CancellationToken ct) => Task.CompletedTask;
     }

backend/tests/Health.Tests/diet_commentary_tests.cs

@@ -0,0 +1,56 @@
+using Health.Application.AI;
+using Health.Domain.Entities;
+using Health.Domain.Enums;
+
+namespace Health.Tests;
+
+public sealed class DietCommentaryTests
+{
+    [Fact]
+    public void FoodDescription_ContainsOnlyStructuredFoodData()
+    {
+        var result = DietCommentaryPolicy.BuildFoodDescription(
+        [
+            new DietCommentaryFood("番茄炒蛋", "半盘", 220),
+            new DietCommentaryFood("米饭", "一碗", 260),
+        ]);
+
+        Assert.Equal("番茄炒蛋（半盘，220千卡）、米饭（一碗，260千卡）", result);
+        Assert.DoesNotContain("请结合", result);
+    }
+
+    [Fact]
+    public void LegacyArtifact_RequiresEveryUserMessageToUseInternalPrefix()
+    {
+        var artifact = new Conversation
+        {
+            Messages =
+            [
+                new ConversationMessage
+                {
+                    Role = MessageRole.User,
+                    Content = DietCommentaryPolicy.LegacyPromptPrefix + "食物为：米饭",
+                },
+                new ConversationMessage
+                {
+                    Role = MessageRole.Assistant,
+                    Content = "注意搭配蔬菜",
+                },
+            ],
+        };
+        var normal = new Conversation
+        {
+            Messages =
+            [
+                new ConversationMessage
+                {
+                    Role = MessageRole.User,
+                    Content = "我想了解今天的饮食记录",
+                },
+            ],
+        };
+
+        Assert.True(DietCommentaryPolicy.IsLegacyArtifact(artifact.Messages));
+        Assert.False(DietCommentaryPolicy.IsLegacyArtifact(normal.Messages));
+    }
+}

backend/tests/Health.Tests/persistence_pipeline_tests.cs

@@ -1,4 +1,5 @@
 using Health.Application.Medications;
+using Health.Application.AI;
 using Health.Domain.Entities;
 using Health.Domain.Enums;
 using Health.Infrastructure.AI;
@@ -13,6 +14,50 @@ namespace Health.Tests;
 
 public sealed class PersistencePipelineTests
 {
+    [Fact]
+    public async Task ConversationCleanup_DeletesOnlyLegacyDietCommentaryArtifacts()
+    {
+        await using var db = CreateDbContext();
+        var userId = Guid.NewGuid();
+        var artifact = new Conversation
+        {
+            Id = Guid.NewGuid(),
+            UserId = userId,
+            AgentType = AgentType.Default,
+        };
+        artifact.Messages.Add(new ConversationMessage
+        {
+            Id = Guid.NewGuid(),
+            ConversationId = artifact.Id,
+            Role = MessageRole.User,
+            Content = DietCommentaryPolicy.LegacyPromptPrefix + "食物为：米饭",
+        });
+        var normal = new Conversation
+        {
+            Id = Guid.NewGuid(),
+            UserId = userId,
+            AgentType = AgentType.Default,
+        };
+        normal.Messages.Add(new ConversationMessage
+        {
+            Id = Guid.NewGuid(),
+            ConversationId = normal.Id,
+            Role = MessageRole.User,
+            Content = "请分析我今天吃的米饭",
+        });
+        db.Conversations.AddRange(artifact, normal);
+        await db.SaveChangesAsync();
+        var repository = new EfAiConversationRepository(db);
+
+        var deleted = await repository.DeleteLegacyDietCommentaryArtifactsAsync(
+            userId,
+            DietCommentaryPolicy.LegacyPromptPrefix,
+            CancellationToken.None);
+
+        Assert.Equal(1, deleted);
+        Assert.Equal(normal.Id, Assert.Single(db.Conversations).Id);
+    }
+
     [Fact]
     public async Task AiConfirmation_CanOnlyBeTakenOnceByOwner()
     {