WIP: local handoff implementation

Local work on the social.io handoff before merging the claude
worktree branch. Includes the full per-spec Sources/Core/Design
module (8 files), watchOS target under WatchApp/, Live Activity +
widget extension, entitlements, scheme, and asset catalog.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.smartconfig.json

@@ -5,9 +5,19 @@
     "derivedDataPath": "swift/.build/xcode-derived-data",
     "parallelBuilds": true,
     "parallelTests": false,
-    "buildPlatforms": ["macos", "ios", "ipad"],
-    "testPlatforms": ["macos"],
-    "watchPlatforms": ["macos", "ios", "ipad"],
+    "buildPlatforms": [
+      "macos",
+      "ios",
+      "ipad"
+    ],
+    "testPlatforms": [
+      "macos"
+    ],
+    "watchPlatforms": [
+      "macos",
+      "ios",
+      "ipad"
+    ],
     "watchDebounceMs": 1200,
     "defaultPlatform": "macos",
     "app": {
@@ -23,7 +33,11 @@
     "screenshots": {
       "scenariosFile": "swift/Automation/ui-screenshot-routes.txt",
       "outputDir": "/tmp/socialio-ui-review",
-      "reviewPlatforms": ["ios", "ipad", "macos"],
+      "reviewPlatforms": [
+        "ios",
+        "ipad",
+        "macos"
+      ],
       "launchDelayMs": 2000,
       "stepDelayMs": 1200,
       "initialCommand": "socialio://mailbox/inbox",
@@ -36,12 +50,14 @@
     },
     "targets": {
       "ios": {
-        "simulatorName": "iPhone Air",
-        "runtime": "latest"
+        "simulatorName": "iPhone 17 Pro",
+        "runtime": "26.4",
+        "simulatorUDID": "8EBCDD58-34AB-457A-A878-8004A6108CA9"
       },
       "ipad": {
-        "simulatorName": "iPad mini (A17 Pro)",
-        "runtime": "latest"
+        "simulatorName": "iPad Pro 11-inch (M5)",
+        "runtime": "26.4",
+        "simulatorUDID": "4ED4902E-C8EB-444A-A8FF-183ABC08E8C2"
       }
     }
   }