fix(api): resolve Docker startup failures (secrets, Redis, Prisma)

- Pass BETTER_AUTH_SECRET through all 6 docker-compose files to API container
- Fix BullModule to parse VALKEY_URL instead of VALKEY_HOST/VALKEY_PORT,
  matching all other Redis consumers in the codebase
- Migrate Prisma encryption from removed $use() middleware to $extends()
  client extensions (Prisma 6.x compatibility), keeping extends PrismaClient
  pattern with only account and llmProviderInstance getters overridden

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docker-compose.swarm.portainer.yml

@@ -290,6 +290,7 @@ services:
       OIDC_REDIRECT_URI: ${OIDC_REDIRECT_URI:-http://localhost:3001/auth/callback}
       JWT_SECRET: ${JWT_SECRET:-change-this-to-a-random-secret}
       JWT_EXPIRATION: ${JWT_EXPIRATION:-24h}
+      BETTER_AUTH_SECRET: ${BETTER_AUTH_SECRET}
       OLLAMA_ENDPOINT: ${OLLAMA_ENDPOINT:-http://ollama:11434}
       OPENBAO_ADDR: ${OPENBAO_ADDR:-http://openbao:8200}
       ENCRYPTION_KEY: ${ENCRYPTION_KEY}