feat: container management tools in tools/

Shell scripts for build, start, stop, restart, nuke, logs, status.
Shared helpers in _common.sh (colours, compose detection, project root).
Updated CHEATSHEET.md with new tool references.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docs/CHEATSHEET.md

@@ -53,14 +53,21 @@ format = "json"    # JSONL output (default: "text")
 ## Container
 
 ```bash
-make build            # Build image (only for dep changes)
-make up               # Start (podman-compose)
-make down             # Stop
-make logs             # Follow logs
+tools/build              # Build image
+tools/build --no-cache   # Rebuild from scratch
+tools/start              # Start (builds if no image)
+tools/stop               # Stop and remove container
+tools/restart            # Stop + rebuild + start
+tools/restart --no-cache # Full clean restart
+tools/logs               # Tail logs (default 30 lines)
+tools/logs 100           # Tail last 100 lines
+tools/status             # Container, image, mount state
+tools/nuke               # Full teardown (container + image)
 ```
 
 Code, plugins, config, and data are bind-mounted. No rebuild needed for
 code changes -- restart the container or use `!reload` for plugins.
+Rebuild only when `requirements.txt` or `Containerfile` change.
 
 ## Bot Commands