ignoreignore some build

docs/image-build.md

@@ -43,11 +43,15 @@ pull requests do not trigger this workflow.
 
 | Event | Behavior |
 | --- | --- |
-| Push to `main` | Build and push `:latest` |
+| Push to `main` | Build and push `:latest`, unless only ignored paths changed |
 | Manual run on `main` | Build and push `:latest` |
 | Manual run on another branch or tag | Job skipped |
 | Pull request or tag push | No workflow run |
 
+Pushes changing only `docs/**`, `**/*.md`, `dev/**`, or `DB/**` skip the workflow.
+Mixed changes still build if any file is outside those paths. Manual runs are
+unaffected by path filters.
+
 The workflow has three steps: checkout, registry login, and `docker build` /
 `docker push`. It does not publish version/commit tags or multi-platform images.
 Use a runner with the same architecture as your deployment server.