formatString

Pure-Kotlin multiplatform string formatting.

Implements the subset of Java's String.format() patterns used in this codebase:

• %s, %d — positional or sequential string/integer

• %N$s, %N$d — explicit positional string/integer

• %N$.Nf, %.Nf — float with decimal precision

• %x, %X, %08x — hexadecimal (lower/upper, optional zero-padded width)

• %% — literal percent