feat: add Delve debugger support and update entrypoint for debugging

docs/debugging-local-container.md

@@ -0,0 +1,24 @@
+# Debugging the Local Docker Image
+
+Use the `cpmp:local` image as the source of truth and attach VS Code debuggers directly to the running container.
+
+## 1. Enable the debugger
+The image now ships with the Delve debugger. When you start the container, set `CPMP_DEBUG=1` (and optionally `CPMP_DEBUG_PORT`) so CPM+ runs under Delve.
+
+```bash
+docker run --rm -it \
+  --name cpmp-debug \
+  -p 8080:8080 \
+  -p 2345:2345 \
+  -e CPM_ENV=development \
+  -e CPM_DEBUG=1 \
+  cpmp:local
+```
+
+Delve will listen on `localhost:2345`, while the UI remains available at `http://localhost:8080`.
+
+## 2. Attach VS Code
+- Use the **Attach to CPMP backend** configuration in `.vscode/launch.json` to connect the Go debugger to Delve.
+- Use the **Open CPMP frontend** configuration to launch Chrome against the management UI.
+
+These launch configurations assume the ports above are exposed. If you need a different port, set `CPMP_DEBUG_PORT` when running the container and update the Go configuration's `port` field accordingly.