Mark as a test fixture with its own property_patches itest

- "fixture": true keeps the mod out of --all-mods and every game, so its
  wildcard patches of all characters and items no longer leak into
  unrelated tests; it loads only with --with-mods=test_defaults_and_patches.
- PropertyPatchesTest (--itest=property_patches) checks the merged
  entities; the manifest declares the sources and every mod whose
  entities the patches touch.

manifest.json

@@ -3,7 +3,17 @@
   "name": "Test Defaults and Patches",
   "version": "1.0.0",
   "author": "ct",
-  "description": "Test mod demonstrating property patches system with wildcard and targeted patches",
+  "description": "Test fixture of the property patches system: a targeted patch (Marao, food/ration) and wildcard patches of every character and item. Marked as a fixture, so --all-mods and games never load it; the property_patches itest loads it explicitly (--with-mods=test_defaults_and_patches --itest=property_patches) and checks the merged entities.",
   "category": "other",
-  "depends": ["visual_novel_core>=1"]
+  "depends": [
+    "visual_novel_core>=1",
+    "murakami>=1",
+    "cooking>=1",
+    "characters_base>=1",
+    "items_base>=1"
+  ],
+  "fixture": true,
+  "sources": [
+    "src/*.cs"
+  ]
 }