chore: remove the opencode service

docs/opencode/known-noise-xdg-open.md

@@ -1,11 +0,0 @@
-# Known noise: `xdg-open` stack trace on start
-
-Applies to `opencode/compose.yml`.
-
-The container logs a Bun stack trace ending in
-`Executable not found in $PATH: "xdg-open"` on every start. `opencode web`
-tries to open the UI in a local browser; there isn't one. It is noise — the
-server is already listening by then, and the container keeps running.
-
-Installing `xdg-utils` would silence it at the cost of pulling X11 in and
-tripling the image, which is not worth it for a log line.