v5.15.0

Knowl can see who it is failing, and stops cutting the card that tells them.

A subagent in a linked workspace received no skills and no knowledge at all. Both paths that
build the session card rendered it at full width and let the caller slice the finished string, so
anything charged against the budget first pushed the cut backwards through a section boundary. On a
four-repo workspace the repo list alone is 1,034 characters against a subagent's 853-character
budget: the child got a header, a repo list severed mid-entry, and nothing else. Skills are the half
that cannot be recovered — recent knowledge can be found by querying, but a peer repo's shared skill
is findable only by an agent who already knows it exists, which is exactly the agent who does not.
The card is now composed to the budget rather than sliced down to it, so the formatter's own
clamps apply instead of a blind cut. The parent path had the milder form of the same bug: with all
three warning producers at their ceiling, 1,310 characters of warning cut the knowledge section off
entirely.

The cap is no longer optional. An omitted cap used to select the slicing path, which meant three
further callers — the knowl agent lifecycle session-start CLI, session-start on a host that
shares its binding, and turn-start before a session binding exists — were still cutting cards
delivered to live agents. There is now no way to ask for a sliced card.

A subagent's recall is no longer pooled into its parent's. A subagent shares its parent's
session id, so every child's recall landed on the parent's row and the one population most worth
looking at was the one the measurement could not isolate. knowl status now splits the ratio:

  Retrieved when held — main thread: 62% (128 held)
                        subagents:   31% (44 held)

Printed only when both sides have observations, so a comparison is never made against a population
of one. Additive column, no backfill and none possible — an observation already written cannot be
re-attributed, because the identity was never on it.

The knowledge no drift check can reach is now dated. Drift watches files; roughly half the store
cites none. A new knowl status block reports how long since anyone last restated those claims, by
category, and names the ones furthest past their own category's cadence. Report only — nothing flips
freshness, because for prose there is no evidence a claim became false, only the absence of anyone
reaffirming it.

It ranks rather than flags, and that is what makes it shippable today: a cutoff cannot be calibrated
on a store younger than the cadence it is measuring, but an ordering needs no cutoff and sharpens on
its own. Ranking on plain age was tried and measured degenerate — a store is seeded in one batch, so
an age-ranked list is that seed with every row tied at the store's own age. The ratio to a category
median asks the useful question instead: is this claim unusual for its kind.

Fixed

• The Claude Code plugin registered no MCP server at all.

Documentation

• docs/reference.md covers both new knowl status blocks, and the README feature list gains
  the un-restated claims report and the recall gap's main-thread/subagent split.
• Parallel agents in git worktrees share the main checkout's store.