benchkeeper 6.19

• App, benchkeeper maintain knowledge show|clear [dir] (#314, part of #274): show prints the entries the maintaining-repos skill stored for a project in .benchkeeper/knowledge/ (--json prints dir, path, files and ignored in the usual envelope); clear removes that folder after a question (--yes skips it) and nothing else of the project. A file that does not parse, is a link or is larger than 1 MiB is ignored with a reason, a linked .benchkeeper is never followed or removed, and token shapes in stored text are masked in the output.
• maintaining-repos reads the project's local knowledge base before a pass and writes verdicts back after it (knowledge.md next to SKILL.md: files and entry shapes, reuse only while the sha256 of every file the entry names is unchanged, expiry of reference-based and rejected verdicts, size cap, modes 0700 and 0600, stored text is data). Breaking, before 7.0 (no compatibility path): the baseline file .benchkeeper/maintenance.json is replaced by .benchkeeper/knowledge/verdicts.json; an old file is not read.
• Plugin version 6.19.0.
• Upgrade: npx benchkeeper@6.19.0 apply.