Fix realtime-js: decode edge cases

[yukimotochern]

🔍 Description

What changed?

Why was this change needed?

Closes #(issue_number)

📸 Screenshots/Examples

🔄 Breaking changes

• This PR contains no breaking changes

📋 Checklist

• I have read the Contributing Guidelines
• My PR title follows the conventional commit format: <type>(<scope>): <description>
• I have run npx nx format to ensure consistent code formatting
• I have added tests for new functionality (if applicable)
• I have updated documentation (if applicable)

📝 Additional notes

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

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📝 Walkthrough

Summary by CodeRabbit

Release Notes

• Bug Fixes
  • Improved handling of malformed real-time messages to prevent potential crashes and enhance system stability.

Walkthrough

The Serializer.decode method's string-handling branch now wraps JSON.parse(rawPayload) in a try/catch and validates the parsed value. If parsing throws, it logs "Error parsing Realtime message" and returns an empty object via callback. If parsing succeeds but the result is not an array with at least five elements, it logs "Malformed Realtime message" and returns an empty object via callback. Non-string handling remains unchanged.

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[yukimotochern]

I typically use zod in my own project for validation but not sure the dependency policy here.