fix(backend): include drizzle migrations in Docker image

The Dockerfile was missing the drizzle/migrations directory, causing
fresh Docker installations to skip all database migrations. This left
the database without core tables (roles, queueJobs, globalSettings, etc.)
resulting in 500 errors on API requests.

Also fixes docker-compose.yml:
- Use 127.0.0.1 instead of localhost in healthcheck (IPv6 resolution issue)
- Add default for DEPLOYSTACK_ENCRYPTION_SECRET to suppress warning
- Remove obsolete version attribute

Closes #546

Author: Lasim

docker-compose.yml

@@ -45,7 +45,7 @@ services:
       postgres:
         condition: service_healthy
     healthcheck:
-      test: ["CMD", "curl", "-f", "http://localhost:3000/"]
+      test: ["CMD", "wget", "-q", "-O", "/dev/null", "http://127.0.0.1:3000/"]
       interval: 30s
       timeout: 10s
       retries: 3