fix(cli): parse tempradio args without mutable copy and document timeout cap

[robekl]

Summary

This PR hardens tempradio CLI parsing by removing mutable-copy tokenization and parsing arguments directly from the input command string.

It also updates CLI docs to match the new timeout validation range.

What Changed

• Replaced strcpy(tmp, &command[10]) + parseTextParts(...) for tempradio parsing with a non-mutating parser that reads directly from command + 10.
• Added dedicated parsing helpers for float and integer fields with separator/trailing-input validation.
• Kept existing radio parameter range checks and existing success/error reply behavior.
• Updated docs to state timeout_mins must be 1-32767.

Why

The previous tempradio path copied unbounded user input into a fixed-size internal buffer. This could overflow internal object memory for long CLI input.

The new parser avoids copying entirely for this command path and validates structure explicitly.

Behavior Notes

• tempradio now requires well-formed comma-separated input and rejects malformed trailing content.
• timeout_mins is now explicitly capped at 32767 minutes, matching implementation and avoiding unsafe large time conversions.

Validation

• Reviewed call path and parser behavior in CommonCLI::handleCommand.
• Confirmed documentation now reflects enforced timeout range.