[ingvarch]

What changes

The rest of the code quality audit of 2026-10-16: one bug and two refactors.

• A feed that :events did not take is closed now. The messages that bring an opened stream share one method, release(), and the route that closes streams no page took matches that interface, not a list of types. The old list had three of the four kinds, so a second feed opened next to the one :events reads stayed open.
• The verbs of the command line (:find, :gc, :run) come from one table: their names, whether they change the cluster, and what they run. Read-only mode is checked once, for every verb that writes, and a test goes over the table, so a new verb is covered too. A user sees one change: :gc in read-only mode now says read-only: :gc is off, the way a key and :run say it.
• config.Load takes the path of its file, as settings.Load does, and main passes it. Config.Save, which only tests called, is gone; the tests write through Snapshot and Write, the way the UI does, and no longer set XDG_CONFIG_HOME for it. A new test in cmd/urga checks that urga reads the session from urga/config.json in the config folder, since the file name now lives in main.

Closes #117
Closes #123
Closes #124

Checklist

• The test for this change was written first and failed
• make check is green
• The title is a conventional commit: feat(ui): ..., fix(nomad): ...