Add a combined 'all' push remote and document the new push habit

Pushing to rocky alone doesn't trigger CI (Gitea can't see that private bare
repo), and two separate git push commands are easy to half-remember. 'all'
has two push URLs (rocky, gitea) so one push updates the staging checkout's
source and triggers CI together. Deliberately excludes origin (GitHub)
pending the still-open question about that repo's ownership/involvement.

docs/CONTINUOUS_INTEGRATION.md

@@ -73,6 +73,22 @@ The expected steady state is:
 - `runner`: `Up`; and
 - `weathertool-ci-rocky-01`: `Idle` in Gitea when no job is queued.
 
+## Triggering CI
+
+CI only runs on a push (or PR) reaching the `gitea` remote — pushing to
+`rocky` alone does not trigger it, since Gitea has no visibility into that
+private bare repo. To avoid needing two separate `git push` commands (and
+forgetting one), a combined `all` remote pushes to both `rocky` and `gitea`
+in one command:
+
+```bash
+git push all codex/staging-baseline
+```
+
+`all` deliberately does not include `origin` (the GitHub
+`guntisdev/WeatherTool` repo) — see `DEVELOPMENT_AND_STAGING.md`'s commit
+workflow section for why.
+
 `Idle` is healthy. It means the runner is authenticated and polling for
 work. The runner is available only while the coding PC, Docker, and these
 containers are running.