Function parse_loop_args 

pub fn parse_loop_args(args: &str) -> (Duration, String)

Parse the argument string from /loop <args>.

Supports three forms:

• Leading interval: /loop 5m check the build → (5m, “check the build”)
• Trailing clause: /loop check the build every 2h → (2h, “check the build”)
• No interval: /loop check the build → (10m default, “check the build”)

Returns (interval, prompt).