feat(AI): LLM 迁移到 mlx-swift-lm 2.31.3 + Qwen3.5-2B

将 SPM 依赖从 mlx-swift-examples 2.29.1 迁到改名延续仓库 mlx-swift-lm
2.31.3(含 qwen3_5 架构、旧 loadContainer API 兼容),文本 LLM 由
Qwen3-1.7B 换为 Qwen3.5-2B-4bit(走 qwen3_5→Qwen35Model 文本路径)。
连带 mlx-swift 0.29.1→0.31.4,顺修弃用 API:
- MLX.GPU.clearCache() → MLX.Memory.clearCache()
- MLX.GPU.set(cacheLimit:) → MLX.Memory.cacheLimit

更新 ModelManifest(.llm 文件清单+精确字节数,~1.63GiB)、ModelManifestTests、
HealthExport.modelTag 默认值。App BUILD SUCCEEDED + ModelManifestTests 通过。

保留作 MNN 改造的 GPU 兜底基线。

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

康康.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved

@@ -1,13 +1,13 @@
 {
-  "originHash" : "6b8265ebd61c6fdfca835dd1f90f17439ca9abc5c11a8b7b5db8790be0349e4d",
+  "originHash" : "facc0ac7c70363ea20f6cd1235de91dea6b06f0d00190946045a6c8ae753abc2",
   "pins" : [
     {
-      "identity" : "gzipswift",
+      "identity" : "eventsource",
       "kind" : "remoteSourceControl",
-      "location" : "https://github.com/1024jp/GzipSwift",
+      "location" : "https://github.com/mattt/EventSource.git",
       "state" : {
-        "revision" : "731037f6cc2be2ec01562f6597c1d0aa3fe6fd05",
-        "version" : "6.0.1"
+        "revision" : "a3a85a85214caf642abaa96ae664e4c772a59f6e",
+        "version" : "1.4.1"
       }
     },
     {
@@ -15,17 +15,35 @@
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/ml-explore/mlx-swift",
       "state" : {
-        "revision" : "072b684acaae80b6a463abab3a103732f33774bf",
-        "version" : "0.29.1"
+        "revision" : "dc43e62d7055353c7f99fa071a4e71d29dfddc44",
+        "version" : "0.31.4"
       }
     },
     {
-      "identity" : "mlx-swift-examples",
+      "identity" : "mlx-swift-lm",
       "kind" : "remoteSourceControl",
-      "location" : "https://github.com/ml-explore/mlx-swift-examples",
+      "location" : "https://github.com/ml-explore/mlx-swift-lm",
       "state" : {
-        "revision" : "9bff95ca5f0b9e8c021acc4d71a2bbe4a7441631",
-        "version" : "2.29.1"
+        "revision" : "25b00d4e22e61ec9c41efda47990cd2084ec87ff",
+        "version" : "2.31.3"
+      }
+    },
+    {
+      "identity" : "swift-asn1",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/apple/swift-asn1.git",
+      "state" : {
+        "revision" : "eb50cbd14606a9161cbc5d452f18797c90ef0bab",
+        "version" : "1.7.0"
+      }
+    },
+    {
+      "identity" : "swift-atomics",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/apple/swift-atomics.git",
+      "state" : {
+        "revision" : "b601256eab081c0f92f059e12818ac1d4f178ff7",
+        "version" : "1.3.0"
       }
     },
     {
@@ -37,6 +55,24 @@
         "version" : "1.5.1"
       }
     },
+    {
+      "identity" : "swift-crypto",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/apple/swift-crypto.git",
+      "state" : {
+        "revision" : "1b6b2e274e85105bfa155183145a1dcfd63331f1",
+        "version" : "4.5.0"
+      }
+    },
+    {
+      "identity" : "swift-huggingface",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/huggingface/swift-huggingface.git",
+      "state" : {
+        "revision" : "b721959445b617d0bf03910b2b4aced345fd93bf",
+        "version" : "0.9.0"
+      }
+    },
     {
       "identity" : "swift-jinja",
       "kind" : "remoteSourceControl",
@@ -46,6 +82,15 @@
         "version" : "2.3.6"
       }
     },
+    {
+      "identity" : "swift-nio",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/apple/swift-nio.git",
+      "state" : {
+        "revision" : "57c0a08a331aaea9f5d7a932ad94ef43be942a95",
+        "version" : "2.100.0"
+      }
+    },
     {
       "identity" : "swift-numerics",
       "kind" : "remoteSourceControl",
@@ -55,13 +100,31 @@
         "version" : "1.1.1"
       }
     },
+    {
+      "identity" : "swift-system",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/apple/swift-system.git",
+      "state" : {
+        "revision" : "669763cfd5806a67e21972d7e5e2d6b80b1ea985",
+        "version" : "1.6.5"
+      }
+    },
     {
       "identity" : "swift-transformers",
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/huggingface/swift-transformers",
       "state" : {
-        "revision" : "a2e184dddb4757bc943e77fbe99ac6786c53f0b2",
-        "version" : "1.0.0"
+        "revision" : "58c4bc11963a140358d791f678a60a2745a23146",
+        "version" : "1.2.1"
+      }
+    },
+    {
+      "identity" : "yyjson",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/ibireme/yyjson.git",
+      "state" : {
+        "revision" : "8b4a38dc994a110abaec8a400615567bd996105f",
+        "version" : "0.12.0"
       }
     }
   ],