Fix : Render provider (support OAuth + new GraphQL behavior)

[Oscar-Quiloulou]

🛠️ Summary

This PR updates the Render provider to support both classic email‑password accounts and OAuth‑based accounts (GitHub / Google), following Render’s recent GraphQL changes.

Render removed all legacy validation mutations and now exposes only the signUp mutation. This mutation always returns a GraphQL error, but the error message contains a JSON payload that reveals the actual email state.

This patch restores correct behavior for detecting:

• existing emails (classic accounts)

• existing emails (OAuth accounts)

• available emails

It also adds the internal x-render-client-* headers required by Render’s new API.

🔍 Background

Render recently changed its GraphQL API:

• all legacy mutations (validateEmail, checkEmail, validateSignup) were removed

• signUp is now the only mutation that exposes email existence

• signUp always returns an error, but the error message contains structured JSON

• OAuth accounts (GitHub/Google) are not stored in the same table as classic accounts

• therefore, OAuth emails return "email":"invalid" even though they exist

Render’s current behavior returns one of the following payloads inside the GraphQL error:

json

{"email": "exists"}

json

{"email": "invalid"}

json

{"hcaptcha_token": "invalid"}

These correspond to:

Payload | Meaning | Interpretation -- | -- | -- {"email":"exists"} | Classic Render account | taken {"email":"invalid"} | OAuth account or unknown | taken {"hcaptcha_token":"invalid"} | Valid but unused email | available

🔧 Changes

• replaced all deprecated mutations with signUp

• added required x-render-client-* headers

• parsed JSON error payloads returned by Render

• treated OAuth accounts ("email":"invalid") as taken

• improved compatibility with Render’s current API

💡 Why this matters

Before this patch, the Render provider always failed with:

Code

GraphQL validation failed

or incorrectly marked OAuth accounts as invalid.

With this fix, the provider correctly detects:

• classic accounts

• OAuth accounts

• available emails

and is fully functional again.

🧪 Testing

Tested against:

• classic Render accounts

• OAuth GitHub accounts

• non‑existent emails

• random valid emails

All cases return the correct result.