fix: use bookworm base for blogpost; route receiver history via :18080

- blogpost: python:3.11-slim-bullseye is EOL (apt 404s), switch to bookworm
- utils/bashrc: host port 80 is taken by Traefik/Coolify, preexec posts to :18080
- ignore receiver .venv

utils/bashrc

@@ -1,2 +1,2 @@
 source /root/.preexec.sh
-preexec() { curl -s -X POST  -H 'Content-Type: application/json' -d "{\"log\": \"[$(date +'%Y-%m-%d %H:%M:%S')][$(hostname)] $1\"}" http://host.docker.internal/history > /dev/null; }
+preexec() { curl -s -X POST  -H 'Content-Type: application/json' -d "{\"log\": \"[$(date +'%Y-%m-%d %H:%M:%S')][$(hostname)] $1\"}" http://host.docker.internal:18080/history > /dev/null; }