fix: don't point the Ralph @fix_plan.md watcher at a remote session's directory

A remote-SSH session's workingDir is a path on the remote host, but
setupSessionListeners() handed it to the Ralph tracker, whose
RalphFixPlanWatcher reads and fs.watch()es it on the LOCAL disk. Where the
path does not exist locally (the usual case), every server start logged

  [RalphFixPlanWatcher] Could not watch @fix_plan.md: Error: ENOENT ...

once per remote session; where a same-named local directory did exist, it
watched the wrong tree. Setting the path also made the tracker treat that
unreadable file as authoritative (isFileAuthoritative is "a path is set"),
which switched off its output-based todo completion for remote sessions.

Skip the tracker's working dir for remote sessions, next to the existing
external-CLI skip.

src/web/server.ts

@@ -1989,8 +1989,10 @@ export class WebServer extends EventEmitter {
     this.runSummaryTrackers.set(session.id, summaryTracker);
     summaryTracker.recordSessionStarted(session.mode, session.workingDir);
 
-    // Set working directory for Ralph tracker to auto-load @fix_plan.md (not supported for external CLIs)
-    if (!isExternalCliMode(session.mode)) {
+    // Set working directory for Ralph tracker to auto-load @fix_plan.md (not supported for external CLIs).
+    // A remote session's workingDir is a path on the remote host, and the watcher reads and
+    // fs.watch()es it on the LOCAL disk, so it is skipped there too.
+    if (!isExternalCliMode(session.mode) && !session.remote) {
       session.ralphTracker.setWorkingDir(session.workingDir);
     }