A clicked path that points OUTSIDE the case directory goes through the attachment
routes (the frontend's `_isExternalPreviewPath` sends every absolute path not under
`workingDir` to `POST /attachments`), and those had the same local-`fs` assumption
as file-raw: `realpathSync`/`fs.stat` on a path that only exists on the remote host,
so the file never opened — the case the #415 report was actually about.
- `registerExternalAttachment()` accepts `remote` and resolves through
`remoteProbePaths` (canonical path, size/mtime, kind, plus the workspace root for
the confinement check). Everything around it — blocklist, extension allowlist,
workspace confinement, registry/dedupe — is now shared by both branches, so the
remote path cannot drift from the local one.
- The by-id routes (`raw`, `preview`, `thumbnail`), the metadata poll and the
attachment history list resolve over ssh too. `raw` streams with the same
Range contract as file-raw; `preview` (office) and `thumbnail` answer 400 for a
remote record; an unreachable host answers 502, a vanished file 404.
- Which host a record is read from follows the SESSION, never the path string: the
same absolute path is a different file on each host, and a remote session never
falls back to a local file with that name.
- Codex generated artifacts keep force-workspace confinement for a remote case: the
well-known artifact directories are anchored at THIS host's home, so only a file
inside the remote workspace is trusted.
Still local-only by design: writes, office conversion, thumbnails, the file
tree/picker and tail-file.
A remote case's workingDir is an absolute path on the remote host, but the
file read routes resolved it with local `fs`: `validateSessionFilePath`'s
realpathSync fails for a path that does not exist on the Codeman host, so
every preview of an agent-written file answered "File not found" (#415).
Add src/remote-files.ts as the single remote-read layer, built on the same
buildSshConnectionArgs() the launch uses:
- remoteProbePaths(): ONE round trip returning realpath + stat for the
requested path AND the workspace root, so containment is checked against a
remotely canonicalized root (a symlinked remotePath is ordinary).
- remoteCreateReadStream(): streams the body (cat, or tail -c +N | head -c L
for a Range) with nothing buffered in memory, and reaps the ssh child when
the response ends so an aborted download cannot orphan it.
- remoteReadFile(): bounded read for file-content.
file-raw, file-content, file-preview and file-thumbnail now share one local/
remote target resolution. Guards keep their local strength: lexical pre-check,
remote realpath, workspace containment, sensitive-path blocklist, and the size
cap applied to the remote size before any bytes are read. An unreachable host
answers 502 with the remote reason instead of a misleading 404. Nothing is ever
copied to the Codeman host and there is NO local fallback (an sshfs mount of
the same tree must not shadow the remote bytes).
Deliberately unchanged: writes (edit=1 / PUT now answer 400 explicitly while
the viewer hides its Edit affordance), office previews, thumbnails, file tree,
picker, external attachment registration and tail-file stay local-only.
Randalix