#82 feat: add EntityError derive macro for OpenAPI error docs

[RAprogramm]

Summary

• New #[derive(EntityError)] macro for error enums
• Parse #[status(code)] for HTTP status codes
• Use doc comments as OpenAPI descriptions
• Generate helper struct for response documentation

Usage

#[derive(Debug, Error, ToSchema, EntityError)]
pub enum UserError {
    /// User with this email already exists
    #[error("Email already exists")]
    #[status(409)]
    EmailExists,

    /// User not found
    #[error("User not found")]
    #[status(404)]
    NotFound,
}

// Generates UserErrorResponses struct

Test plan

• 4 unit tests for error parsing
• clippy clean
• All 102 tests pass

Closes #82

[codecov]

Codecov Report

❌ Patch coverage is 67.46988% with 27 lines in your changes missing coverage. Please review.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
crates/entity-derive-impl/src/error.rs	70.00%	24 Missing ⚠️
crates/entity-derive-impl/src/lib.rs	0.00%	3 Missing ⚠️

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