feat: scaffold Expo Prebuild project with all v1 screens and services

Sets up the full bincio-rec source tree: Zustand recording store with
haversine stats, background GPS via expo-task-manager, BLE scan/subscribe
for HR and power, GPX writer with Garmin extensions, SQLite recordings
list, multipart upload to bincio-activity, React Navigation stack with
bottom tabs, and build instructions in README.md.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app.json

@@ -1,25 +1,60 @@
 {
   "expo": {
-    "name": "bincio_rec_scaffold",
-    "slug": "bincio_rec_scaffold",
+    "name": "bincio-rec",
+    "slug": "bincio-rec",
     "version": "1.0.0",
     "orientation": "portrait",
     "icon": "./assets/icon.png",
-    "userInterfaceStyle": "light",
+    "userInterfaceStyle": "dark",
     "ios": {
-      "supportsTablet": true
+      "supportsTablet": false,
+      "bundleIdentifier": "com.bincio.rec",
+      "infoPlist": {
+        "NSLocationWhenInUseUsageDescription": "bincio-rec uses your location to record your activity track.",
+        "NSLocationAlwaysAndWhenInUseUsageDescription": "bincio-rec uses your location in the background to record your activity track.",
+        "UIBackgroundModes": ["location"]
+      }
     },
     "android": {
+      "package": "com.bincio.rec",
       "adaptiveIcon": {
-        "backgroundColor": "#E6F4FE",
+        "backgroundColor": "#111111",
         "foregroundImage": "./assets/android-icon-foreground.png",
         "backgroundImage": "./assets/android-icon-background.png",
         "monochromeImage": "./assets/android-icon-monochrome.png"
       },
-      "predictiveBackGestureEnabled": false
+      "predictiveBackGestureEnabled": false,
+      "permissions": [
+        "ACCESS_FINE_LOCATION",
+        "ACCESS_BACKGROUND_LOCATION",
+        "FOREGROUND_SERVICE",
+        "FOREGROUND_SERVICE_LOCATION",
+        "BLUETOOTH",
+        "BLUETOOTH_ADMIN",
+        "BLUETOOTH_SCAN",
+        "BLUETOOTH_CONNECT"
+      ]
     },
     "web": {
       "favicon": "./assets/favicon.png"
-    }
+    },
+    "plugins": [
+      "expo-sqlite",
+      [
+        "expo-location",
+        {
+          "locationAlwaysAndWhenInUsePermission": "bincio-rec records your GPS track during activities.",
+          "isAndroidBackgroundLocationEnabled": true,
+          "isAndroidForegroundServiceEnabled": true
+        }
+      ],
+      [
+        "expo-notifications",
+        {
+          "icon": "./assets/icon.png",
+          "color": "#3b82f6"
+        }
+      ]
+    ]
   }
 }