Adopt root-level tsswift app layout

Move the app payload under swift/ while keeping git, package.json, and .smartconfig.json at the repo root. This standardizes the Swift app setup so build, test, run, and watch workflows match the other repos.

.smartconfig.json

@@ -0,0 +1,27 @@
+{
+  "@git.zone/tsswift": {
+    "defaultScheme": "IDPGlobal",
+    "defaultConfiguration": "Debug",
+    "derivedDataPath": "swift/.build/xcode-derived-data",
+    "parallelBuilds": true,
+    "parallelTests": false,
+    "buildPlatforms": ["macos", "ios", "ipad"],
+    "testPlatforms": ["macos"],
+    "watchPlatforms": ["macos", "ios", "ipad"],
+    "watchDebounceMs": 1200,
+    "defaultPlatform": "macos",
+    "app": {
+      "bundleId": "global.idp.app"
+    },
+    "targets": {
+      "ios": {
+        "simulatorName": "iPhone Air",
+        "runtime": "latest"
+      },
+      "ipad": {
+        "simulatorName": "iPad mini (A17 Pro)",
+        "runtime": "latest"
+      }
+    }
+  }
+}