feat: Email templates, bulk delete, communication credits, plan features

- Add email template presets for Browse Templates tab (12 templates)
- Add bulk selection and deletion for My Templates tab
- Add communication credits system with Twilio integration
- Add payment views for credit purchases and auto-reload
- Add SMS reminder and masked calling plan permissions
- Fix appointment status mapping (frontend/backend mismatch)
- Clear masquerade stack on login/logout for session hygiene
- Update platform settings with credit configuration
- Add new migrations for Twilio and Stripe payment fields

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

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

frontend/package-lock.json

@@ -12,6 +12,8 @@
         "@dnd-kit/utilities": "^3.2.2",
         "@stripe/connect-js": "^3.3.31",
         "@stripe/react-connect-js": "^3.3.31",
+        "@stripe/react-stripe-js": "^5.4.1",
+        "@stripe/stripe-js": "^8.5.3",
         "@tanstack/react-query": "^5.90.10",
         "@types/react-syntax-highlighter": "^15.5.13",
         "axios": "^1.13.2",
@@ -1474,6 +1476,29 @@
         "react-dom": ">=16.8.0"
       }
     },
+    "node_modules/@stripe/react-stripe-js": {
+      "version": "5.4.1",
+      "resolved": "https://registry.npmjs.org/@stripe/react-stripe-js/-/react-stripe-js-5.4.1.tgz",
+      "integrity": "sha512-ipeYcAHa4EPmjwfv0lFE+YDVkOQ0TMKkFWamW+BqmnSkEln/hO8rmxGPPWcd9WjqABx6Ro8Xg4pAS7evCcR9cw==",
+      "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": "8.5.3",
+      "resolved": "https://registry.npmjs.org/@stripe/stripe-js/-/stripe-js-8.5.3.tgz",
+      "integrity": "sha512-UM0GHAxlTN7v0lCK2P6t0VOlvBIdApIQxhnM3yZ2kupQ4PpSrLsK/n/NyYKtw2NJGMaNRRD1IicWS7fSL2sFtA==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=12.16"
+      }
+    },
     "node_modules/@tailwindcss/node": {
       "version": "4.1.17",
       "resolved": "https://registry.npmjs.org/@tailwindcss/node/-/node-4.1.17.tgz",