```

feat(AI): 集成MNN推理引擎替换MLX作为主AI运行时

- 引入MNN(alibaba) + Arm SME2 + CPU作为主AI运行时，支持A19/iPhone17的
  SME2和A17的NEON加速
- 添加MLX Swift作为兜底GPU推理方案，实现双后端切换机制
- 使用单一Qwen3.5-2B多模态模型(1.2GB)，替代原有的LLM+VL分离架构
- 实现InferenceEngine.current引擎选择逻辑，真机默认MNN，模拟器回退MLX
- 更新AIAgent架构，通过MNNLLMBridge(ObjC++) → MNNBackend进行推理
- 修改队列机制防止并发推理导致OOM，使用信号量闸门控制显存占用
- 更新文档中的技术栈说明、模块边界和周次交付计划
```

康康Tests/ModelsSchemaTests.swift

@@ -17,6 +17,7 @@ struct ModelsSchemaTests {
             UserProfile.self,
             MetricReminder.self,
             CustomMonitorMetric.self,
+            Medication.self,
         ])
         let config = ModelConfiguration(schema: schema, isStoredInMemoryOnly: true)
         return try ModelContainer(for: schema, configurations: [config])
@@ -190,4 +191,42 @@ struct ModelsSchemaTests {
         #expect(fetched.bloodTypeRaw == "A")
         #expect(fetched.chronicConditions == ["高血压"])
     }
+
+    @Test func medicationRoundtripAndDetailLine() throws {
+        let container = try makeContainer()
+        let ctx = ModelContext(container)
+
+        let med = Medication(name: "缬沙坦胶囊", strength: "80mg×7粒", usage: "一日一次,一次一粒")
+        ctx.insert(med)
+        try ctx.save()
+
+        let fetched = try #require(try ctx.fetch(FetchDescriptor<Medication>()).first)
+        #expect(fetched.name == "缬沙坦胶囊")
+        #expect(fetched.detailLine == "80mg×7粒 · 一日一次,一次一粒")
+        #expect(fetched.updatedAt == fetched.createdAt)
+    }
+
+    @Test func medicationDetailLineOmitsEmptyParts() {
+        #expect(Medication(name: "维生素C").detailLine == "")
+        #expect(Medication(name: "钙片", strength: "600mg").detailLine == "600mg")
+    }
+
+    @Test func cascadeDeleteMedicationRemovesAssets() throws {
+        let container = try makeContainer()
+        let ctx = ModelContext(container)
+
+        let med = Medication(name: "二甲双胍缓释片", strength: "0.5g×30片")
+        let asset = Asset(relativePath: "med-1.jpg", bytes: 2048)
+        ctx.insert(asset)
+        med.assets.append(asset)
+        ctx.insert(med)
+        try ctx.save()
+        #expect(med.assets.count == 1)
+
+        ctx.delete(med)
+        try ctx.save()
+
+        #expect(try ctx.fetch(FetchDescriptor<Medication>()).isEmpty)
+        #expect(try ctx.fetch(FetchDescriptor<Asset>()).isEmpty)
+    }
 }