The "Add to Context" command and the active-editor pin-selection suggestion both create selection attachments but used the basename only (e.g. assist.ts:47). OpenCode synthesizes its Read call from that filename, so the directory was lost and the model could read or edit the wrong file when names collide.
Use the workspace-relative path (asRelativePath(uri, false)) in both paths so the filename carries the directory and the two paths produce identical filenames, restoring attachment dedup.
Fixes#1914
Ibrahim Khan
de92b8fef4