Syntax errors.New fix

[MichaelBoegner]

Summary

This PR standardizes error message capitalization by converting all capitalized error messages to lowercase. This change improves consistency across the codebase by following Go's convention that error messages should start with lowercase letters.

What changed

• Converts all error messages from title case to lowercase
• Updates both production code and mock repositories
• Maintains consistent error message formatting across all modules

[Copilot]

Pull Request Overview

This PR standardizes error message capitalization by converting all capitalized error messages to lowercase. This change improves consistency across the codebase by following Go's convention that error messages should start with lowercase letters.

• Converts all error messages from title case to lowercase
• Updates both production code and mock repositories
• Maintains consistent error message formatting across all modules

Reviewed Changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
user/service.go	Updates JWT token error message to lowercase
user/repository_mock.go	Converts all mock error messages to lowercase
user/model.go	Updates account deletion error message to lowercase
token/repository_mock.go	Standardizes mock error messages to lowercase
interview/repository_mock.go	Converts mock database error messages to lowercase
conversation/repository_mock.go	Updates all mock error messages to lowercase format

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