feat(deploy): the CI runner's window by hand, halkyon-ci-now (ADR 0039, D6)

Rests the heavy sidecars, runs every queued job, then stops the runner and
starts the sidecars again however it ends; from melchior through
systemd-run, so a closed laptop doesn't end it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

deploy/host/README.md

@@ -200,6 +200,7 @@ databases, the first start, the first operator, the backups). Then:
      deploy/runner/halkyon-night.service deploy/runner/halkyon-night.timer \
      deploy/runner/halkyon-morning.service deploy/runner/halkyon-morning.timer \
      /etc/systemd/system/
+   sudo install -m 755 deploy/runner/ci-now.sh /usr/local/sbin/halkyon-ci-now
    ```
 
    In Forgejo (`code.halkyon.app`, the repository's *Settings › Actions › Runners*): a new
@@ -213,6 +214,7 @@ databases, the first start, the first operator, the backups). Then:
    systemctl list-timers 'forgejo-runner*' 'halkyon-*'   # 01:55, 02:00, 05:00
    ```
 
-   To try it by day: `sudo systemctl start forgejo-runner` (it stops itself three hours
-   later) and push a branch. The job's first step, *Sandbox*, fails if the runner
+   To run the queue by day: `sudo halkyon-ci-now` (`deploy/runner/ci-now.sh`, which says
+   how from melchior too) rests the heavy sidecars, runs every queued job and starts them
+   again; `--keep-sidecars` keeps them, the job then slower, in swap. The job's first step, *Sandbox*, fails if the runner
    reaches the instance, the home network, the tunnel or any IPv6 address, or sees `/data`.