Complete Docker compose deployment setup

- Add an API container entrypoint that waits for PostgreSQL, runs Prisma migrations, seeds demo data, and then starts NestJS.

- Keep Prisma CLI and seed dependencies available in the API runtime image and copy seed source dependencies into the container.

- Add Docker Compose healthchecks and health-based startup ordering for PostgreSQL, API, and Nginx web services.

- Add Docker initialization environment switches for migrations, seed, and startup retries.

- Add a dedicated Docker deployment guide covering services, ports, initialization, HTTPS, production variables, backup, restore, and troubleshooting.

- Update README, AGENTS, installation, deployment, progress, and environment example docs for the Dockerized workflow.

scripts/docker-api-entrypoint.sh

@@ -0,0 +1,30 @@
+#!/bin/sh
+set -e
+
+run_with_retry() {
+  name="$1"
+  shift
+  attempts="${DOCKER_STARTUP_RETRIES:-30}"
+  delay="${DOCKER_STARTUP_RETRY_DELAY:-2}"
+  current=1
+
+  until "$@"; do
+    if [ "$current" -ge "$attempts" ]; then
+      echo "Docker startup step failed after ${attempts} attempts: ${name}" >&2
+      return 1
+    fi
+    echo "Docker startup step not ready (${current}/${attempts}): ${name}. Retrying in ${delay}s..." >&2
+    current=$((current + 1))
+    sleep "$delay"
+  done
+}
+
+if [ "${RUN_DB_MIGRATIONS:-true}" = "true" ]; then
+  run_with_retry "prisma migrate deploy" npx prisma migrate deploy --schema server/prisma/schema.prisma
+fi
+
+if [ "${RUN_DB_SEED:-true}" = "true" ]; then
+  run_with_retry "prisma db seed" npm run prisma:seed
+fi
+
+exec node server/dist/main.js