Several sessions of one app: a session's working folder names its agent when that agent runs in the same app (MCP server and hooks), an i_am tool binds a session explicitly, the doctor checks second sessions against their app's install, and an agent that left the roster can still be uninstalled

harbor/install.py

@@ -380,7 +380,7 @@ def install(host, agent=None, project=None, dry_run=False, remove=False, python=
             p = projects.resolve()
         except projects.ProjectError:
             p = None
-    if p and agent not in p.ai_names:
+    if p and agent not in p.ai_names and not remove:      # an agent that left the roster can still be uninstalled
         raise InstallError(f"{agent} is not an agent of project {p.name} ({', '.join(p.ai_names)})")
     cmd = launcher(python)
     plan = Plan(host, dry_run)