feat: add code-server service and repo scaffolding

Set up the per-service layout: each service directory holds compose.yml
with a committed .env.example and a gitignored .env.

Add code-server as the first service, plus a README and CLAUDE.md
documenting that these files target Coolify/Dokploy and deliberately
omit ports and restart policies.

.gitignore

@@ -0,0 +1,23 @@
+# Secrets: every service keeps its own .env next to its compose.yml
+.env
+*.env
+!.env.example
+!*.env.example
+
+# Compose override files are host-specific
+compose.override.yml
+compose.override.yaml
+docker-compose.override.yml
+docker-compose.override.yaml
+
+# Bind-mount data directories, if a service uses one instead of a named volume
+data/
+*/data/
+
+# OS / editor noise
+.DS_Store
+Thumbs.db
+desktop.ini
+*.swp
+.idea/
+.vscode/