🐛 fix: Include Nested Paths in Config Validation Errors

[dustinhealy]

Summary

Config field validation currently drops nested Zod issue paths, so failures inside objects and arrays only identify the top-level field. This makes it difficult to locate the specific invalid value.

This PR preserves each issue path when formatting validation errors. A missing nested field now reports its array index and property path, while top-level validation messages retain their existing format.

Change Type

• Bug fix (non-breaking change which fixes an issue)

Testing

Added regression coverage for a missing required field inside a custom-endpoint array entry.

• bun run test src/server/config.test.ts (497 tests passed)
• bunx eslint src/server/config.ts src/server/config.test.ts
• bunx prettier --check src/server/config.ts src/server/config.test.ts

Test Configuration:

• Bun 1.3.3

Checklist

• My code adheres to this project's style guidelines
• I have performed a self-review of my own code
• My changes do not introduce new warnings
• I have written tests demonstrating that my changes are effective or that my feature works
• Local unit tests pass with my changes