🐛 Fix silent download failure and cosmetic naming bugs 🐛

Fixes three bugs discovered during live container testing.
The critical bug was a bash post-increment no-op: `exitCode=$((exitCode++))`
assigns the *old* value back to the variable, so exitCode stays 0 even
when a download fails. This caused the Docker build to succeed silently
when the gitea binary download failed, publishing a broken image to Docker Hub.
- rootfs/root/docker/setup/05-custom.sh: change exitCode=$((exitCode++)) to
exitCode=$((exitCode + 1)) in both the gitea and act_runner failure handlers
- rootfs/usr/local/bin/entrypoint.sh: change CONTAINER_NAME and description
from "archlinux" (copied template default) to "gitea"
- rootfs/usr/local/etc/docker/init.d/08-gitea.sh: remove leading space from
[ -d " /config/ssh" ] path test so the directory existence check is correct

.claude/
rootfs/root/docker/setup/05-custom.sh
rootfs/usr/local/bin/entrypoint.sh
rootfs/usr/local/etc/docker/init.d/08-gitea.sh

.claude/settings.local.json

@@ -0,0 +1,7 @@
+{
+  "permissions": {
+    "allow": [
+      "Bash(script-lint *)"
+    ]
+  }
+}