Companion keeper: after a restart the panel opens the Companion that ran last if it is not running

- only in the watchdog's first 10 minutes, never another version, never during an upgrade
- SC verified end to end; laptop SSH to the SC Macs; configs synced

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

settings/campus.py

@@ -292,6 +292,9 @@ def upgrade_companion(base, say=print, source=None):
     import urllib.request
     root = os.path.expanduser("~/Library/Application Support/companion")
     app = "/Applications/Companion 5.0.7.app"
+    # The watchdog's CompanionKeeper must not reopen the old Companion in the middle of this.
+    with open(os.path.join(PARENT, "companion-upgrading"), "w") as f:
+        f.write(str(time.time()))
     if not os.path.exists(app) and source:              # standalone: the .dmg (or .zip) downloaded from bitfocus.io
         install_companion_from(source, app, say)
     if not os.path.exists(app):
@@ -323,6 +326,10 @@ def upgrade_companion(base, say=print, source=None):
         try:
             discover.companion_get({"companion": {}}, "/api/connections", 2)
             say("Companion 5.0.7 is running. In System Settings > General > Login Items, replace the old Companion with 5.0.7.")
+            try:
+                os.remove(os.path.join(PARENT, "companion-upgrading"))
+            except OSError:
+                pass
             return True
         except OSError:
             time.sleep(1)