docs(deploy): correct the image size, and say what a missing rgcom runner does

The image measures 757 MB, not the ~600 MB the requirements table guessed. And
until the rgcom runner exists the deploy job simply queues, which is worth stating
in both the workflow and DEPLOY.md: build has already published the image by then,
so the manual pull works throughout and the queued job goes when the runner does.

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

.gitea/workflows/build-image.yml

@@ -114,6 +114,10 @@ jobs:
     runs-on: rgcom
     # Guard against a workflow_dispatch fired from a branch: only main is deployed.
     if: github.ref == 'refs/heads/main'
+    # Until a runner with this label exists, this job simply QUEUES. That is the
+    # intended behaviour and it breaks nothing: `build` has already published the
+    # image, so `docker compose pull && up -d` by hand is available the whole time,
+    # and the queued job runs the moment the runner registers.
 
     steps:
       - name: Pull the fresh image and recreate the container

DEPLOY.md

@@ -39,7 +39,7 @@ Very little, and that is deliberate (`PLAN.md` §6).
 |---|---|
 | **Runtime** | Docker, with Compose v2 (`docker compose`, not `docker-compose`) |
 | **CPU / RAM** | One core and 512 MB is comfortable. Every page but two is prerendered HTML |
-| **Disk** | ~600 MB for the image, plus a SQLite file that will not reach a megabyte |
+| **Disk** | ~750 MB for the image, plus a SQLite file that will not reach a megabyte |
 | **Network out** | Only to pull the image. The running site makes no outbound request of any kind |
 | **Network in** | One HTTP port, reached by your reverse proxy |
 | **Database** | None. No MariaDB, no Redis, no second service |
@@ -309,6 +309,10 @@ container. Without it the job starts in a container with no Docker socket and no
 Make sure the user the runner runs as can talk to Docker (`docker ps` succeeds) and can read and
 write `/opt/runicgateway.com`.
 
+**Until that runner exists, the deploy job just queues**, and nothing is harmed: the image has
+already been built and pushed by the time it would run, so the manual update below works throughout,
+and the queued job goes as soon as the runner registers.
+
 **To update by hand instead** — always available, and what you do if the runner is down:
 
 ```bash