Add devcontainer setup

.devcontainer/Dockerfile

@@ -0,0 +1,3 @@
+FROM mcr.microsoft.com/vscode/devcontainers/base:ubuntu-24.04
+
+RUN apt install curl ca-certificates git

.devcontainer/boot

@@ -0,0 +1,9 @@
+#!/bin/bash
+
+echo "Updating RubyGems..."
+gem update --system -N
+
+echo "Installing dependencies..."
+bundle install
+
+echo "Done!"

.devcontainer/devcontainer.json

@@ -0,0 +1,50 @@
+{
+  "name": "Ruby development",
+  "dockerComposeFile": "docker-compose.yml",
+  "service": "app",
+  "workspaceFolder": "/workspaces/${localWorkspaceFolderBasename}",
+  "features": {
+    "ghcr.io/devcontainers/features/github-cli:1": {},
+    "ghcr.io/devcontainers/features/common-utils:2": {
+      "username": "vscode",
+      "userUid": 1001,
+      "userGid": 1001,
+      "installZsh": true,
+      "installOhMyZsh": true,
+      "configureZshAsDefaultShell": true,
+      "upgradePackages": true
+    },
+    "ghcr.io/rocker-org/devcontainer-features/apt-packages:1": {
+      "packages": "libpq-dev, libvips"
+    },
+    "ghcr.io/devcontainers/features/ruby:1": {
+      "version": "3.4.1"
+    },
+    "ghcr.io/devcontainers/features/node:1": {},
+    "ghcr.io/devcontainers-extra/features/zsh-plugins:0": {
+      "username": "vscode",
+      "plugins": "bundler rails ruby yarn git"
+    },
+    "ghcr.io/devcontainers/features/sshd:1": {
+      "version": "latest"
+    }
+  },
+
+  // Configure tool-specific properties.
+  "customizations": {
+    "vscode": {
+      "extensions": ["Shopify.ruby-lsp", "EditorConfig.EditorConfig"]
+    }
+  },
+
+  // Use 'forwardPorts' to make a list of ports inside the container available locally.
+  // This can be used to network with other containers or the host.
+  "forwardPorts": [5433],
+
+  "postStartCommand": "git config --global --add safe.directory ${containerWorkspaceFolder}",
+
+  // Use 'postCreateCommand' to run commands after the container is created.
+  "postCreateCommand": ".devcontainer/boot",
+
+  "remoteUser": "vscode"
+}

.devcontainer/docker-compose.yml

@@ -0,0 +1,8 @@
+services:
+  app:
+    build:
+      context: ..
+      dockerfile: .devcontainer/Dockerfile
+    volumes:
+      - ../..:/workspaces:cached
+    command: sleep infinity