feat: Store timestamps as strings in the database, which was causing postgres errors.

docker-compose.yaml

@@ -0,0 +1,31 @@
+services:
+  db:
+    image: docker.io/postgres:18
+    restart: unless-stopped
+    env_file: .env
+    volumes:
+      - ./data:/var/lib/postgresql
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U ductcalc"]
+      interval: 5s
+      timeout: 5s
+      retries: 5
+  
+  app:
+    build:
+      dockerfile: docker/Dockerfile
+      context: .
+    restart: unless-stopped
+    env_file: .env
+    environment:
+      - POSTGRES_HOSTNAME=db
+    depends_on:
+      db:
+        condition: healthy
+    ports:
+      - 8081:8080
+    healthcheck:
+      test: curl --fail --silent http://0.0.0.0:8080/health || exit 1
+      interval: 1m
+      timeout: 10s
+      retries: 3