Update TestPlan.xctestplan + tests + docs

Summary:
- Tests: TestPlan.xctestplan
- Docs: Testing

Stats:
- 2 files changed, 41 insertions(+)

Documentation/Testing.md

@@ -31,3 +31,20 @@ Run all tests from the package root:
 ```bash
 swift test
 ```
+
+### Xcode Test Plans
+For granular control (enabling/disabling specific tests or trying different configurations), use **Xcode Test Plans**:
+
+1. **Create a Test Plan**:
+   - Go to **Product > Test Plan > New Test Plan...**
+   - Save it in your `Tests/` directory as `LocalData.xctestplan`.
+2. **Configure Tests**:
+   - Open the `.xctestplan` file.
+   - You will see a list of all test targets, classes, and individual test methods.
+   - Use the **check/uncheck** boxes to include or exclude specific tests.
+3. **Run the Plan**:
+   - Hold down the **Play** button for the test action or go to **Product > Test > [Plan Name]**.
+   - You can also run it via terminal: `xcodebuild test -plan LocalData`.
+
+> [!TIP]
+> Test plans are excellent for CI/CD environments where you might want to run a "Smoke Test" plan (subset of tests) or a "Full Integration" plan.

Tests/TestPlan.xctestplan

@@ -0,0 +1,24 @@
+{
+  "configurations" : [
+    {
+      "id" : "D2951487-F388-4A07-A1E8-3A4B179619B9",
+      "name" : "Configuration 1",
+      "options" : {
+
+      }
+    }
+  ],
+  "defaultOptions" : {
+    "testTimeoutsEnabled" : true
+  },
+  "testTargets" : [
+    {
+      "target" : {
+        "containerPath" : "container:",
+        "identifier" : "LocalDataTests",
+        "name" : "LocalDataTests"
+      }
+    }
+  ],
+  "version" : 1
+}