feat: integrate Stripe for embedded checkout; update billing API to return client_secret and adjust checkout flow in components

package-lock.json

@@ -1,16 +1,18 @@
 {
   "name": "pulse-frontend",
-  "version": "0.6.0-alpha",
+  "version": "0.7.0-alpha",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "pulse-frontend",
-      "version": "0.6.0-alpha",
+      "version": "0.7.0-alpha",
       "dependencies": {
         "@ciphera-net/ui": "^0.0.57",
         "@ducanh2912/next-pwa": "^10.2.9",
         "@radix-ui/react-icons": "^1.3.0",
+        "@stripe/react-stripe-js": "^5.6.0",
+        "@stripe/stripe-js": "^8.7.0",
         "axios": "^1.13.2",
         "country-flag-icons": "^1.6.4",
         "d3-scale": "^4.0.2",
@@ -2715,6 +2717,30 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/@stripe/react-stripe-js": {
+      "version": "5.6.0",
+      "resolved": "https://registry.npmjs.org/@stripe/react-stripe-js/-/react-stripe-js-5.6.0.tgz",
+      "integrity": "sha512-tucu/vTGc+5NXbo2pUiaVjA4ENdRBET8qGS00BM4BAU8J4Pi3eY6BHollsP2+VSuzzlvXwMg0it3ZLhbCj2fPg==",
+      "license": "MIT",
+      "dependencies": {
+        "prop-types": "^15.7.2"
+      },
+      "peerDependencies": {
+        "@stripe/stripe-js": ">=8.0.0 <9.0.0",
+        "react": ">=16.8.0 <20.0.0",
+        "react-dom": ">=16.8.0 <20.0.0"
+      }
+    },
+    "node_modules/@stripe/stripe-js": {
+      "version": "8.7.0",
+      "resolved": "https://registry.npmjs.org/@stripe/stripe-js/-/stripe-js-8.7.0.tgz",
+      "integrity": "sha512-tNUerSstwNC1KuHgX4CASGO0Md3CB26IJzSXmVlSuFvhsBP4ZaEPpY4jxWOn9tfdDscuVT4Kqb8cZ2o9nLCgRQ==",
+      "license": "MIT",
+      "peer": true,
+      "engines": {
+        "node": ">=12.16"
+      }
+    },
     "node_modules/@surma/rollup-plugin-off-main-thread": {
       "version": "2.2.3",
       "resolved": "https://registry.npmjs.org/@surma/rollup-plugin-off-main-thread/-/rollup-plugin-off-main-thread-2.2.3.tgz",