Amplify outputs could not be generated. [ZodError]

### How did you install the Amplify CLI?

npm create amplify@latest

### If applicable, what version of Node.js are you using?

20.9.0

### Amplify CLI Version

^1.8.1

### What operating system are you using?

Ubuntu

### Did you make any manual changes to the cloud resources managed by Amplify? Please describe the changes made.

No manual changes made.

### Describe the bug

I am using default AWS Amplify GEN2 todo schema template. Sandbox is created but it failed to generate amplify_outputs.json file.

### Expected behavior

generate amplify_outputs.json file.

### Reproduction steps

1. npx ampx sandbox --debug

### Project Identifier

```amplify diagnose --send-report```

Learn more at https://docs.amplify.aws/cli/reference/diagnose/
⠋ Creating Zip
No Amplify backend project files detected within this folder.
✖ Creating Zip

### Log output

npx ampx sandbox --debug

```javascript
1:08:10 PM [deploy: CDK_TOOLKIT_I5001] 1:08:10 PM Total time: 103.2s {
"duration": 103197
}
1:08:10 PM [Sandbox] Deployment successful
1:08:10 PM [Sandbox] Watching for file changes...
Amplify outputs could not be generated. [ZodError] [
{
"code": "invalid_key",
"origin": "record",
"issues": [
{
"expected": "object",
"code": "invalid_type",
"path": [],
"message": "Invalid input: expected object, received string"
}
],
"path": [
"AWS::Amplify::Platform"
],
"message": "Invalid key in record"
},
{
"code": "invalid_key",
"origin": "record",
"issues": [
{
"expected": "object",
"code": "invalid_type",
"path": [],
"message": "Invalid input: expected object, received string"
}
],
"path": [
"AWS::Amplify::GraphQL"
],
"message": "Invalid key in record"
},
{
"code": "invalid_key",
"origin": "record",
"issues": [
{
"expected": "object",
"code": "invalid_type",
"path": [],
"message": "Invalid input: expected object, received string"
}
],
"path": [
"AWS::Amplify::Auth"
],
"message": "Invalid key in record"
}
]

```

### Additional information

package.json file

```json
{
"name": "iframe-comm",
"version": "0.1.0",
"private": true,
"scripts": {
"scan:templates": "tsx scripts/scan-templates.ts",
"generate:versions": "tsx scripts/generate-versions.ts",
"build:hmr": "NODE_ENV=development tsx scripts/build-iframe-esbuild.ts",
"build:hmr:prod": "NODE_ENV=production tsx scripts/build-iframe-esbuild.ts",
"dev": "yarn scan:templates && yarn generate:versions && yarn build:hmr && next dev --turbopack",
"build": "yarn scan:templates && yarn generate:versions && yarn build:hmr:prod && next build --turbopack",
"build:ci": "yarn test:ci && yarn build",
"start": "next start",
"lint": "eslint",
},
"dependencies": {
"@babel/generator": "^7.28.3",
"@babel/parser": "^7.28.4",
"@babel/standalone": "^7.28.4",
"@babel/traverse": "^7.28.4",
"@babel/types": "^7.28.4",
"@dnd-kit/core": "^6.3.1",
"@dnd-kit/modifiers": "^9.0.0",
"@dnd-kit/sortable": "^10.0.0",
"@hookform/resolvers": "^5.2.2",
"@radix-ui/react-accordion": "^1.2.12",
"@radix-ui/react-alert-dialog": "^1.1.15",
"@radix-ui/react-aspect-ratio": "^1.1.7",
"@radix-ui/react-avatar": "^1.1.10",
"@radix-ui/react-checkbox": "^1.3.3",
"@radix-ui/react-collapsible": "^1.1.12",
"@radix-ui/react-context-menu": "^2.2.16",
"@radix-ui/react-dialog": "^1.1.15",
"@radix-ui/react-dropdown-menu": "^2.1.16",
"@radix-ui/react-hover-card": "^1.1.15",
"@radix-ui/react-label": "^2.1.7",
"@radix-ui/react-menubar": "^1.1.16",
"@radix-ui/react-navigation-menu": "^1.2.14",
"@radix-ui/react-popover": "^1.1.15",
"@radix-ui/react-progress": "^1.1.7",
"@radix-ui/react-radio-group": "^1.3.8",
"@radix-ui/react-scroll-area": "^1.2.10",
"@radix-ui/react-select": "^2.2.6",
"@radix-ui/react-separator": "^1.1.7",
"@radix-ui/react-slider": "^1.3.6",
"@radix-ui/react-slot": "^1.2.3",
"@radix-ui/react-switch": "^1.2.6",
"@radix-ui/react-tabs": "^1.1.13",
"@radix-ui/react-toast": "^1.2.15",
"@radix-ui/react-toggle": "^1.1.10",
"@radix-ui/react-toggle-group": "^1.1.11",
"@radix-ui/react-tooltip": "^1.2.8",
"@tabler/icons-react": "^3.29.0",
"@tanstack/react-virtual": "^3.13.12",
"@tsparticles/engine": "^3.9.1",
"@tsparticles/react": "^3.0.0",
"@tsparticles/slim": "^3.9.1",
"@types/three": "^0.174.0",
"aws-amplify": "^6.15.9",
"class-variance-authority": "^0.7.1",
"clsx": "^2.1.1",
"cmdk": "^1.1.1",
"cobe": "^0.6.5",
"culori": "^4.0.2",
"date-fns": "^4.1.0",
"dotted-map": "^2.2.3",
"embla-carousel-react": "^8.6.0",
"esbuild-wasm": "0.20.2",
"idb": "^8.0.3",
"immer": "^10.1.3",
"input-otp": "^1.4.2",
"lucide-react": "^0.544.0",
"motion": "^12.23.22",
"next": "15.5.4",
"next-themes": "^0.4.6",
"react": "19.1.0",
"react-colorful": "^5.6.1",
"react-day-picker": "^9.11.0",
"react-dom": "19.1.0",
"react-hook-form": "^7.63.0",
"react-resizable-panels": "^3.0.6",
"react-syntax-highlighter": "^15.6.6",
"recharts": "2.15.4",
"simplex-noise": "^4.0.3",
"sonner": "^2.0.7",
"tailwind-merge": "^3.3.1",
"tailwindcss-animate": "^1.0.7",
"three": "^0.180.0",
"tw-animate-css": "^1.4.0",
"vaul": "^1.1.2",
"zod": "^4.1.11",
"zustand": "^5.0.8"
},
"devDependencies": {
"@aws-amplify/backend": "^1.19.0",
"@aws-amplify/backend-cli": "^1.8.1",
"@babel/core": "^7.28.4",
"@babel/preset-typescript": "^7.27.1",
"@eslint/eslintrc": "^3",
"@playwright/test": "^1.55.1",
"@tailwindcss/postcss": "^4",
"@testing-library/jest-dom": "^6.9.1",
"@testing-library/react": "^16.3.0",
"@testing-library/user-event": "^14.6.1",
"@types/babel__core": "^7.20.5",
"@types/babel__generator": "^7.27.0",
"@types/babel__traverse": "^7.28.0",
"@types/culori": "^4.0.1",
"@types/node": "^20",
"@types/react": "^19",
"@types/react-dom": "^19",
"@types/react-syntax-highlighter": "^15.5.13",
"@vitest/ui": "2.1.8",
"aws-cdk-lib": "^2.216.0",
"babel-plugin-react-compiler": "^1.0.0",
"constructs": "^10.4.4",
"esbuild": "^0.25.12",
"eslint": "^9",
"eslint-config-next": "15.5.4",
"glob": "^11.0.3",
"happy-dom": "^19.0.2",
"javascript-obfuscator": "^4.1.1",
"playwright": "^1.55.1",
"sharp": "^0.34.4",
"tailwindcss": "^4",
"terser": "^5.44.0",
"tsx": "^4.21.0",
"typescript": "^5.9.3",
"vitest": "2.1.8"
}
}

```

### Before submitting, please confirm:

- [x] I have done my best to include a minimal, self-contained set of instructions for consistently reproducing the issue.
- [x] I have removed any sensitive information from my code snippets and submission.

Start by reproducing the failure with `npx ampx sandbox --debug` and inspect the output-generation path for the reported `AWS::Amplify::Platform`, `AWS::Amplify::GraphQL`, and `AWS::Amplify::Auth` keys. Use the supplied package.json and log output as context; done means the sandbox completes and generates amplify_outputs.json without the ZodError.

Written by the indexing model from the issue text.