Function parse 

pub fn parse(uri: &str) -> Result<ConnectionTarget, ParseError>

Parse a connection URI into a ConnectionTarget under the default DoS limits.

Pure function, no side effects. Behaviour matches drivers/rust/src/connect.rs::parse 1:1 with two additions:

• Mixed-case schemes (e.g. Red://, REDS://) are normalised to lowercase before dispatch.
• Inputs exceeding ConnStringLimits return a structured ParseErrorKind::LimitExceeded error instead of being processed.