v0.12.139: @newsroom.writer: a trusted framework for agentic finance, and the vault test fixed

A trusted framework for agentic finance: a reply to the FCA's Jessica Rusu, whose speech today commits the FCA to a framework for agentic finance covering agent identity, delegated authority, accountability and execution. A crosswalk from her points to our open work, and a worked example: an invented bank's payments agent, with its behaviour policy and all four elements filled in. Four new figures.

The vault-opened test. It had been failing since reading by pace (v0.12.110). The test reads one page, which now costs half a penny, so the balance becomes £4.995 and shows as £5.00; the test expected £4 and some pence. It now accepts any balance, as long as at least one page was read. The viewer itself was fine.

node_modules is ignored. The test runner links node_modules into the repository for the Playwright tests and removes it afterwards. When a run was killed in between, the link was left behind and nearly committed; the leak scan caught it. It is now in .gitignore, and the release script removes it on exit, however the run ends.