Add Stripe embedded onboarding

- Update StripeConnectOnboarding component with embedded flow
- Add new Stripe routes and service methods for embedded onboarding
- Update EarningsStatus and EarningsDashboard to support new flow
- Add required frontend dependencies

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontend/package-lock.json

@@ -9,6 +9,8 @@
       "version": "0.1.0",
       "dependencies": {
         "@googlemaps/js-api-loader": "^1.16.10",
+        "@stripe/connect-js": "^3.3.31",
+        "@stripe/react-connect-js": "^3.3.31",
         "@stripe/react-stripe-js": "^3.3.1",
         "@stripe/stripe-js": "^5.2.0",
         "@testing-library/dom": "^10.4.0",
@@ -3326,6 +3328,23 @@
       "integrity": "sha512-9BCxFwvbGg/RsZK9tjXd8s4UcwR0MWeFQ1XEKIQVVvAGJyINdrqKMcTRyLoK8Rse1GjzLV9cwjWV1olXRWEXVA==",
       "license": "MIT"
     },
+    "node_modules/@stripe/connect-js": {
+      "version": "3.3.31",
+      "resolved": "https://registry.npmjs.org/@stripe/connect-js/-/connect-js-3.3.31.tgz",
+      "integrity": "sha512-vjsZbatveSMoceOKZHt4eImmlBQla112OV9+enxcZUC1dGziTl2J2E3iH3n01yx9nu9ziesMJnSh/Y2d62TA/Q==",
+      "license": "MIT"
+    },
+    "node_modules/@stripe/react-connect-js": {
+      "version": "3.3.31",
+      "resolved": "https://registry.npmjs.org/@stripe/react-connect-js/-/react-connect-js-3.3.31.tgz",
+      "integrity": "sha512-lzJbFdnlUxyILuEjdE9CqYhGq10XPvz89m/Phe/9aqXhLi02eIbaNHZOL+WQo1NMOGWeLjASnMCUagCZwoOsiA==",
+      "license": "MIT",
+      "peerDependencies": {
+        "@stripe/connect-js": ">=3.3.29",
+        "react": ">=16.8.0",
+        "react-dom": ">=16.8.0"
+      }
+    },
     "node_modules/@stripe/react-stripe-js": {
       "version": "3.9.2",
       "resolved": "https://registry.npmjs.org/@stripe/react-stripe-js/-/react-stripe-js-3.9.2.tgz",