[BUG] Error messages in Azerbaijani should be English for international users #39

Issue

All error messages in the codebase are in Azerbaijani language:

ValidatorError::UnknownType(string) => write!(f, "Gözlənilməyən token '{string}'"),
ParserError::UnexpectedToken(span, token) => write!(f, "{span} Gözlənilməyən token '{token}'"),

Impact

• International users cannot understand errors
• Makes debugging difficult for non-Azerbaijani speakers
• Reduces project accessibility

Recommendation

Switch all error messages to English while preserving the structure and clarity.

Files

• crates/parser/src/errors.rs
• crates/validator/src/errors.rs
• crates/tokenizer/src/errors.rs
• compiler/src/errors.rs

Labels: bug, i18n, good first issue