fix(input): return (nil, err) on read_query_answer timeout

[tanmayrajurkar]

Replace error() in read_query_answer() with
return nil, "timeout: no response from terminal".

This aligns the function with our (value, err) return
convention which has beed used throughout the input module and CLI widgets.
query() already uses this pattern.

Adds LDoc notes for the error return and Busted tests covering
timeout behavior in both read_query_answer() and query().

There is No behavioral change except preventing a hard crash on timeout.

[Tieske]

this code is actually there on purpose. It's unclear to me wehther this could ever happen. Hence the "this is unexpected" error, to ensure we'd get feedback if it ever did happen.

That said, whenever you think something cannot happen, it typically happens. So maybe this is a good change. Wdyt?

[tanmayrajurkar]

@Tieske I understand that using error() makes sure we notice if something truely happen which is causing a crash.

My reasoning was mostly about API boundaries most of the input layer follows our new (value, err) pattern, so throwing here forces downstream callers to wrap in pcall(), which feels inconsistent with the rest of the module’s public surface.