docs: add TrueNAS Docker network fix and package linking notes

- Docker address pool 0.0.0.0 causes unreachable gateway on TrueNAS 25.10
- Gitea requires manual package-repo linking on first push

gitea-python-ci-cd.md

@@ -551,6 +551,25 @@ CMD ["uvicorn", "your_package.main:app", "--host", "0.0.0.0", "--port", "8080"]
 
 **Registry URL pattern:** `{gitea-host}/{owner}/{repo}:{tag}`
 
+### Docker Network on TrueNAS
+
+If Docker builds fail with `route for the gateway 0.0.0.1 could not be found: network is unreachable`, the Docker address pool is misconfigured. In TrueNAS 25.10+:
+
+1. Go to **Apps → Configuration** (gear icon)
+2. Change Address Pool base from `0.0.0.0` to `172.17.0.0` (keep `/12`, size `24`)
+3. Save — Docker restarts automatically
+
+Verify: `sudo docker run --rm alpine ping -c 1 google.com`
+
+### Package-Repository Linking
+
+Gitea does not auto-link container packages to repositories on first push, even with the `org.opencontainers.image.source` label in the Dockerfile. You must manually link the package once:
+
+1. Go to your profile → **Packages** → click the package
+2. Go to **Settings** → link it to the repository
+
+Subsequent pushes to the same package name stay linked automatically.
+
 ## 8. Release Versioning
 
 | Tag format | Example | Pre-release? | Docker `:latest`? |