fix(terminal): don't ssh-wrap the local runner's own tmux attach

src/panopticon/terminal/console.py

@@ -21,6 +21,7 @@
 
 from __future__ import annotations
 
+import socket as socket_module
 import subprocess
 import sys
 import tempfile
@@ -69,14 +70,21 @@ def switch_to(
     host: str | None = None,
     switch_file: Path,
     detach: Callable[[], None] = _tmux_detach,
+    local_host: Callable[[], str] = socket_module.gethostname,
 ) -> None:
     """The dashboard's `t` hook, run inside its tmux session: record the picked ``session`` for
     the supervisor, then detach this client so the supervisor attaches the task. The dashboard
     process keeps running (detached), so returning to it shows the same live view.
 
-    When ``host`` is set the switch-file carries ``<host>\\t<session>`` so the
-    supervisor can ssh-wrap the attach; a plain ``<session>`` (no tab) means local.
+    ``host`` is the claiming runner's registered hostname (ADR 0013 §6) — populated even for the
+    ordinary local runner. It only means "remote" when it differs from this machine's own
+    hostname (``local_host``, injectable for tests); otherwise it's treated as local so `t` never
+    ssh-wraps a same-machine attach. When genuinely remote, the switch-file carries
+    ``<host>\\t<session>`` so the supervisor can ssh-wrap the attach; a plain ``<session>`` (no
+    tab) means local.
     """
+    if host == local_host():
+        host = None
     switch_file.write_text(f"{host}\t{session}" if host else session)
     detach()
 

tests/test_console.py

@@ -79,11 +79,28 @@ def test_switch_to_with_remote_host_encodes_host_and_session(tmp_path: Path) ->
     # parse it and pass host= to attach_command for the ssh-wrapped attach.
     switch = tmp_path / "switch"
 
-    switch_to("panopticon-t1", host="box.example.com", switch_file=switch, detach=lambda: None)
+    switch_to(
+        "panopticon-t1", host="box.example.com", switch_file=switch, detach=lambda: None,
+        local_host=lambda: "this-machine",
+    )
 
     assert switch.read_text() == "box.example.com\tpanopticon-t1"
 
 
+def test_switch_to_with_own_hostname_is_treated_as_local(tmp_path: Path) -> None:
+    # The ordinary local runner registers its own hostname too (ADR 0013 §6), but that must not
+    # ssh-wrap a same-machine attach: when host == local_host() it's dropped, so the switch-file
+    # carries a plain session (no tab) just like the no-host case.
+    switch = tmp_path / "switch"
+
+    switch_to(
+        "panopticon-t1", host="this-machine", switch_file=switch, detach=lambda: None,
+        local_host=lambda: "this-machine",
+    )
+
+    assert switch.read_text() == "panopticon-t1"
+
+
 def test_supervisor_parses_remote_host_from_switch_file(tmp_path: Path) -> None:
     # run_console_local's attach() closure parses "<host>\t<session>" from the switch-file and
     # passes host= to attach_command; a plain session (no tab) means local (host=None).