A request can carry several of this capability's returns — a model can call search
twice in one response — and the carrier was identified by message alone, so each of
them received the whole capsule. It is selected by message and part now, so exactly
one carries it however many share the request.
The chat TUI passed its persisted state into the run, so tool synchronisation mutated
it in place while the message history was promoted only on success. A cancelled or
failed run therefore kept the evidence the tools had recorded and discarded the
messages that justified it, and the next question derived its identity from the
shorter history: behind the recorded epoch, refused as non-append-only, the
conversation unusable until cleared. The run gets a copy, promoted with the messages
or not at all.
Five decorators had been left attached to a helper by an earlier extraction, which
pytest does not collect, so the resume case they carried was silently untested. The
wire test covers both resume shapes again, no prompt and deferred results.
`_compact_old_tool_returns`, `PRIOR_TURN_NOTICE` and `turn_start` leave
`RAGCapabilityBase`, along with its `wrap_model_request` hook. The evidence
capabilities now retrieve and validate, and nothing else. Registering the compaction
capability is what rewrites a request; leaving it out sends the transcript untouched,
which was never a choice a host could make before.
The boundary is the recorded question identity rather than message shape, so a
resumption compacts what lies below the question in progress instead of switching
compaction off for the whole run. The newest earlier evidence return carries the
capsule and every other becomes a receipt, so one capsule exists by construction and
every return stays paired with its call.
Pictures of cited evidence are fetched through the capability that retrieved them and
re-attached beside the capsule with fresh labels. Ownership of a picture on the wire
requires the machine tag we write and an image directly after it, since neither
position nor prose is proof: several tools' results can arrive in one request, and a
user quoting our wording above their own picture had it removed. A picture that cannot
be fetched or decoded is emitted with neither its image nor its label.
The chat TUI and the example backend register the compactor, being multi-turn.
`client.ask`, `client.analyze` and the MCP tools do not: a single-shot question has
nothing earlier to compact.
