pub fn unwrap_string(s: &str) -> Result<(Vec<u8>, usize), Error>Expand description
Unwrap a v0.11 md1 string into (byte-padded payload bytes, symbol-aligned bit count).
The returned symbol_aligned_bit_count = 5 × data_symbol_count. This is
the EXACT bit length carried by the codex32 BCH layer (rounded up to the
next 5-bit boundary from the actual payload). The caller uses this as
decode_payload’s bit_len so the v11 decoder’s TLV-rollback only sees
≤4 bits of trailing zero-padding (well under the 7-bit threshold).