Search results and capsule entries name the collection they came from; the
images attached beside them carried only the chunk id and reference. Two
collections can return the same picture of the same document, so the two
labels were identical and the model could place neither.
The decision is the one already made for the text: `covers_multiple` at the
generic search tool, and the flag `search_corpus` computed for the capability
tools, which it now returns.
`format_for_agent` named the database whenever one was named, so a search over
a single named database carried a line with nothing to distinguish. It now takes
`include_collection` from the caller, which decides from the search selection
rather than from the hits: a search that could have drawn on two collections
names them even when everything came back from one.
`Collection:` at the model boundary, database in configuration and
administration. `source` on results, documents, citations and analysis
dictionaries is unchanged.
A chunk id is unique within a database and says nothing across them, so a
database copied from another holds the same ids. `qualified_id` keys the
two in-memory identity sites on the database and the id together:
`merge_results` was dropping the second database's result when a query
repeated, and the arrival map that breaks fused score ties was ranking one
of the pair as the other.
Everything serialized records the id alone, so there ambiguity is refused
rather than qualified. `resolve_citations` raises `AmbiguousCitationError`
for a cited id held by two of the databases searched, where it used to
resolve to whichever result came last; `_register_citations` raises for one
already cited from another database in an earlier question. `_cite` turns
both into a `ModelRetry` asking for other evidence. The direct-id fallback
asks every database the question covers instead of taking the first that
answers, so an id no search returned is refused on the same terms.
`all_found` collects them and `first_found` reads its first, which document
reads keep doing on purpose.
Also drop a duplicated 0.77.0 heading from the changelog.
`ask(sources=[…])` scopes a question to some of the configured databases, carried
on the capability state so its search tool searches those. `Citation.source` names
the database a cited chunk came from, resolved from the search results the model
saw, which already carry it.
Context expansion routes each result through the database it came from: a
federating client has no repositories of its own.
The cite fallback, which looks up an id absent from this run's results, searches
only the selected databases. A chunk id says nothing about which database holds
it, so placing one means asking, and asking outside the selection would let a
question scoped to some databases cite another.
The loosely-specced client mocks in the capability tests now say they stand in for
a single-database client. A bare AsyncMock answers any attribute with a truthy
Mock, so `_federated` sent the fallback down the multi-database branch, and
`_source` reached a validated field.
