No staging environment — every change is tested directly against production

Imported from GitHub issue El-SaMa/oma#110 by @El-SaMa.

There is a single environment (192.168.1.240, single docker-compose stack, single Supabase project). E2E tests in CI run against an isolated Playwright/CI environment, not the real stack — meaning the real integration testing (Enhance, database provisioning, etc.) has happened directly against production throughout this project's development.

Fix: stand up a staging stack (separate Supabase project or schema, separate docker-compose profile / subdomain), route deploys through staging first. This is an infrastructure project, not a quick code change — track separately from the code-level fixes in this batch.