Helm chart supports a custom PostgreSQL schema

You can now run Tuist’s primary PostgreSQL schema outside of public, which is useful for self-hosted environments whose database security policies disallow application objects there. The new Helm value postgresql.schema (default public) lets you pick a dedicated namespace, and it is rendered into the server, migration job, build processor, and xcresult processor pods so they all agree on the same boundary. The companion CNPG processor and ops grant scripts accept -v tuist_schema=<schema> so managed CNPG role grants stay aligned. Existing installs that keep the default see no behavioral change.