ci: use the 32 GiB private runner class

Author: javaDevJT

.github/workflows/publish-image.yml

@@ -15,7 +15,7 @@ concurrency:
 jobs:
   publish:
     if: github.ref == 'refs/heads/main'
-    runs-on: truenas-routelisttotesla-storage-64g
+    runs-on: truenas-routelisttotesla-storage-32g
     timeout-minutes: 60
     permissions:
       contents: read
@@ -60,4 +60,4 @@ jobs:
             VCS_REF=${{ github.sha }}
           tags: |
             ghcr.io/javadevjt/routelisttotesla:latest
-            ghcr.io/javadevjt/routelisttotesla:sha-${{ github.sha }}
+            ghcr.io/javadevjt/routelisttotesla:sha-${{ github.sha }}

docs/development-reference.md

@@ -86,6 +86,12 @@ field and ISO date formats. Run from the repository root:
 ./mvnw spring-boot:run
 ```
 
+Image publication uses the private `truenas-routelisttotesla-storage-32g` runner
+class, with the existing disk build cache and GitHub cache fallback. This class
+selects 32 GiB of runner storage; the deployed application's resources are
+configured separately. The operator observed roughly 26 GB peak runner usage
+before requesting this reduction from the 64 GiB class.
+
 The Dockerfile builds the JAR from source in a JDK stage, derives modules with
 `jdeps`, and creates a stripped `jlink` runtime. The final Ubuntu 26.04 image runs
 as UID/GID 10001 and contains neither Maven nor the Java compiler. OCR dependencies