bank.env is line-oriented (name|description|command) so commands with
real newlines spanned records: bank_load truncated the command to its
first line and the remaining script lines became bogus entries. The
bank_get+cut -f3 retrieval path also truncated at embedded tabs.
- lib/bank-lib.sh: v2 format escapes backslash->\\ and newline->\\n
in the command field, writes # BANK_VERSION: 2; bank_load decodes
with printf %b only for v2 files, so existing v1 files load raw
(backward compatible, verified against the real ts-google entry).
- bin/pos-bank: cmd_show/cmd_run/cmd_edit now read fields from the
BANK_* arrays via bank_find instead of bank_get+cut.
- tests/t-bank.sh: +13 checks (71 total) - multiline round-trip exact
bytes, literal backslash-n, v1 raw-backslash compat, v1+re-save
byte-identical, CLI show/run full script.