When codegraph_explore trimmed a rendered file, holes printed as bare
`... (gap) ...` and the header's `+N more` hid the dropped names — while the
footer asked the model to re-explore with exact names it was never given.
Name elided defs in gap markers as `name (file:line)` (using the full file
index, not just the relevance gather), bias the per-file header toward
symbols the trim cut, and point the trimmed-footer at those names.
Co-authored-by: Colby McHenry <colbymchenry@users.noreply.github.com>