Fix: Ensure unique token_version for new user registration

[FaizanKolega]

Security Disclosure Notice

This PR addresses a security vulnerability identified by Kolega.dev as part of our automated security remediation platform validation.

Disclosure Timeline:

• December 10, 2025: Initial responsible disclosure sent to security@nocodb.com with full technical details, reproduction steps, and proposed fixes
• December 16, 2025: Follow-up sent noting the approaching 7-day SLA
• December 19, 2025: No acknowledgment received; PR submitted publicly per standard responsible disclosure practices

We attempted to coordinate privately through NocoDB's official security reporting channel. After exceeding the published response SLA without acknowledgment, we are proceeding with public disclosure to ensure the community can protect their deployments.

Vulnerability identified and fix provided by Kolega.dev (https://kolega.dev/)

Change Summary

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Change type

• feat: (new feature for the user, not a new feature for build script)
• fix: (bug fix for the user, not a fix to a build script)
• docs: (changes to the documentation)
• style: (formatting, missing semi colons, etc; no production code change)
• refactor: (refactoring production code, eg. renaming a variable)
• test: (adding missing tests, refactoring tests; no production code change)
• chore: (updating grunt tasks etc; no production code change)

Test/ Verification

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Additional information / screenshots (optional)

Anything for maintainers to be made aware of