Add postgres to devcontainer / compose

.devcontainer/devcontainer.json

@@ -1,10 +1,13 @@
 {
     "$schema": "https://containers.dev/implementors/json_schema/",
-    "build": {
-        "dockerfile": "Dockerfile"
+    "dockerComposeFile": "docker-compose.yml",
+    "service": "app",
+    "workspaceFolder": "/workspaces/firehose",
+    "remoteUser": "root",
+    "containerEnv": {
+        "DB_HOST": "db",
+        "HOME": "/home/vscode"
     },
-    "remoteUser": "vscode",
-    "runArgs": [],
     "features": {
         "ghcr.io/devcontainers/features/python:1": {},
         "ghcr.io/jsburckhardt/devcontainer-features/uv:1": {},

.devcontainer/docker-compose.yml

@@ -0,0 +1,28 @@
+services:
+  app:
+    build:
+      context: .
+      dockerfile: Dockerfile
+    volumes:
+      - ..:/workspaces/firehose:cached
+    command: sleep infinity
+    depends_on:
+      db:
+        condition: service_healthy
+
+  db:
+    image: postgres:16
+    restart: unless-stopped
+    environment:
+      POSTGRES_USER: postgres
+      POSTGRES_PASSWORD: postgres
+    volumes:
+      - pgdata:/var/lib/postgresql/data
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U postgres"]
+      interval: 5s
+      timeout: 5s
+      retries: 5
+
+volumes:
+  pgdata: