fix(remote): bootstrap PATH consistently for remote tmux (johoja12/Codeman#15)

docs/architecture-invariants.md

@@ -89,6 +89,8 @@ File reads in a remote case are the second ssh surface (see Remote SSH cases bel
 
 **Remote SSH cases** (COD-94/#145): cases can point at a **remote host** (`~/.codeman/remote-hosts.json` + `remote-cases.json` via `src/remote-hosts.ts`; CRUD under `/api/cases` — cases route file). A remote session launches a LOCAL tmux pane running `ssh <host>` that creates a durable REMOTE tmux session on a **dedicated socket** `-L codeman-remote` with name `codeman-ssh-<id>` — deliberately failing the remote Codeman's `SAFE_MUX_NAME_PATTERN` so a Codeman instance on the target host never adopts it; no `-g` global tmux options are set remotely. `remotePath`/`identityFile` are schema-guarded against shell injection (backticks/`$` rejected — same approach as `extraSshOptions`); remote tmux availability is probed via `checkRemoteTmuxAvailable()` in quick-start (ssh args carry `-o ConnectTimeout=10`). Remote claude defaults to an idempotent `claude --session-id <id> || claude --resume <id>` pair under a login shell, so a respawn or reattach continues the SAME conversation rather than starting a fresh one (remote omp gets the same treatment via `--continue`; ⚠️ because the claude arm is an `a || b` pair under `-c`, that pane's PID is the login shell, not the agent); per-host `commands.*` override. Session kill best-effort kills the remote tmux too. `SessionState.remote`/`MuxSession.remote` round-trip through recovery (`restoreMuxSessions` passes `remote` back into the Session constructor). ⚠️ Run flows must route remote cases through `POST /api/quick-start` (which resolves the remote case and skips LOCAL CLI availability gates) — `POST /api/sessions` stat-validates `workingDir` locally and has no `caseName`. `envOverrides`/`effort`/`modelOverride`/`codexConfig`/`geminiConfig` are rejected for remote quick-starts (not silently dropped). UI: Create Case modal → Remote tab. Tests: `test/remote-hosts.test.ts`, `test/remote-ssh-options.test.ts`. ⚠️ **Reading a file in a remote case goes over ssh too** (#415): `src/remote-files.ts` is the single remote-READ layer (`buildRemoteFileCommand` = `buildSshConnectionArgs` + one shellescaped remote command; `remoteProbePaths` returns remote realpath + stat; `remoteCreateReadStream` streams a `Range` via `tail -c +N | head -c L` and its `close()` must be wired to the response's `close` or the ssh child outlives an aborted download). The guard order matches the local path exactly (`validateSessionFilePathLexical` → remote realpath of BOTH file and workspace root → containment → sensitive-path → size cap on the REMOTE size), a request path arrives from the browser and is only ever interpolated as a `shellescape`d token, and an unreachable host answers **502**, never a 404. ⚠️ The probe's symlink resolution FAILS CLOSED: `readlink -f` where it exists, otherwise a `cd -P`/`pwd -P` directory walk plus a bounded plain-`readlink` loop over the last component, and anything it cannot fully resolve is reported unresolvable (404), never as the unresolved string — the first version resolved the directory chain only, so on a host without `readlink -f` a `ws/notes.txt -> ~/.ssh/id_rsa` link passed containment under its own path while `cat` served the key. Records are NUL-separated and index-keyed so a newline in a filename cannot shift the mapping. ⚠️ ssh children are BOUNDED: probes and buffered reads go through `src/remote-ssh-limiter.ts` (a `document-conversion-limiter`-shaped semaphore, default 4), the attachment-history list probes its whole history in ONE batched call (`probeRemoteAttachmentHistory`, threaded into `registerExternalAttachment({remoteProbes})`), and probes chunk at 40 paths — a prompt-injected agent printing `codeman://attach` links in a remote session used to fork one `ssh` per link. `describeExecError` never returns Node's `Command failed: <ssh line>` message (identity path + probe script in a 502 body). The `PUT /file-content` guard sits AHEAD of `validateSessionFilePath`, which resolves LOCALLY, or a same-named local directory (an sshfs mount) takes the write. Under `VITEST` the three IO functions refuse rather than connect. This covers the ATTACHMENT routes too, which is the half a clicked path needs when the file is OUTSIDE the case directory (`_isExternalPreviewPath` sends it to `POST …/attachments`): registration, by-id `raw`, metadata and the history list all resolve over ssh (`registerExternalAttachment({remote})`, `resolveServableRemoteAttachment`), and what decides the host is the SESSION, never the path string — the same absolute path means a different file on each host. Deliberately NOT supported over ssh: writes (`edit=1`/`PUT` answer 400, `editable` is always false), office previews/thumbnails, the file tree/picker, `tail-file`. Tests: `test/remote-files.test.ts`, `test/routes/file-routes-remote.test.ts`.
 
+**Remote tmux PATH**: every SSH command that invokes or locates tmux uses `withRemoteTmuxPath()` (`remote-hosts.ts`) before the complete remote script is shell-escaped: link preflight, launch/attach, alive probes, discovery, history/screen capture, and cleanup. Non-interactive SSH shells can omit Homebrew and per-user binaries even when the user's interactive shell finds them. The wrapper double-quotes the exported PATH value (including inherited PATH) so homes with spaces work under dash; it leaves the existing SSH options, socket/target and inner CLI login-shell handling intact. Keep new remote tmux operations on this same path. `test/remote-tmux-path.test.ts` exercises all builders under real sh/dash with a sparse PATH and a home containing spaces, using offline SSH/tmux stubs. Local and Docker tmux commands keep their own setup.
+
 Further wake-on-LAN detail: the wiring guards in `test/remote-wake.test.ts` are two; the second also pins that `server.ts` holds the registry for its LIFETIME only (`drop` on cleanup, `stop` on shutdown) and never calls a waking method. The create wake is wired in the route rather than the shared session service for exactly the no-timer-wakes reason. No `ServerAliveInterval`, because keepalives move bytes into an idle connection every interval and that is what a byte-threshold idle detector must not read as activity. For a host behind `jumpHost`/`socksProxy`/a `ProxyCommand` option, the probe connects to `host:port`, which such a host does not answer even while ssh works; the registry never gates create/attach on it (`'unprobeable'`), and `/reachability` answers `reachable: null, probeable: false`. The banner keys on a PROVEN `false`, and the banner's 30 s poller runs only for a host with a wake target (a timer connecting to a host Codeman cannot wake is the same timer-driven traffic the keepalive rule forbids).
 
 Input arriving during a wake is buffered: a chunk over 4 KB is dropped whole, never delivered as a fragment, and the route answers `{buffered:true}` / `{buffered:true, dropped:true}` so the caller can tell. It is flushed in order after `reattachRemote()` with `fromUser`; a flush write that fails drops the rest (logged) rather than retaining it for a wake hours later. Send-and-wait blocks instead and answers `OPERATION_FAILED` when the host never returns. ⚠️ In multi-user mode the attach path 403s a non-admin BEFORE the host is looked up: the wake runs an executable, and remote hosts are admin-only infra everywhere else. ⚠️ Browser keystrokes travel over the WebSocket, which deliberately does NOT pass through the registry (that is the hot path), so only the HTTP input path ever queues anything; the banner must not promise queued input for the Wake button. A request that waits on the wake (create/attach, and the button) uses the 40 s `REMOTE_WAKE_REQUEST_READY_TIMEOUT_MS`, not the 90 s session default, because the dashboard's reverse proxy cuts a request at its own 60 s `proxy_read_timeout`. The `remote:` SSE family is session-scoped in multi-user mode; a create/attach wake names its requester (`username`) since it has no session yet. `remote-wake.ts` refuses real IO under `VITEST` like `remote-files.ts`.