fix(dashboard): report application memory accurately

tests/test_dashboard_system_info.py

@@ -31,25 +31,39 @@ def test_dashboard_system_info_returns_runtime_environment(monkeypatch):
 
 
 def test_memory_usage_returns_used_cached_and_available(monkeypatch):
-    """内存统计应拆分已使用、缓存和可用容量，并返回已使用百分比。"""
+    """内存统计应返回应用进程占用以及系统缓存、可用和总容量。"""
+
+    class FakeMemoryInfo:
+        """提供固定进程 RSS 的桩。"""
+
+        rss = 2 * 1024**3
+
+    class FakeProcess:
+        """提供固定进程内存信息的桩。"""
+
+        @staticmethod
+        def memory_info() -> FakeMemoryInfo:
+            """返回固定进程内存信息。"""
+            return FakeMemoryInfo()
 
     class FakeMemory:
         """提供固定系统内存值的桩。"""
 
         total = 16 * 1024**3
-        used = 5 * 1024**3
         cached = 3 * 1024**3
         buffers = 512 * 1024**2
+        available = 7 * 1024**3
 
+    monkeypatch.setattr(system_module.psutil, "Process", FakeProcess)
     monkeypatch.setattr(system_module.psutil, "virtual_memory", FakeMemory)
 
     result = SystemUtils.memory_usage()
 
     assert result.total == 16 * 1024**3
-    assert result.used == 5 * 1024**3
+    assert result.used == 2 * 1024**3
     assert result.cached == int(3.5 * 1024**3)
-    assert result.available == int(7.5 * 1024**3)
-    assert result.usage == 31.25
+    assert result.available == 7 * 1024**3
+    assert result.usage == 12.5
 
 
 def test_monthly_media_statistics_counts_successful_unique_media():