v1 Management REST API ignores x-zitadel-orgid header (v4.15.1), silently returns caller org's data

🏬Self-hosted❌Unsolved🪲Bugs

Hey all, I filed https://github.com/zitadel/zitadel/issues/12482 earlier today and wanted to flag it because the failure mode is silent. On self-hosted v4.15.1, the v1 management REST API ignores the x-zitadel-orgid header entirely: requests always resolve to the caller's org, and even a nonexistent org ID returns 200 with the caller org's data instead of an error. The v2 APIs resolve ctx.orgId correctly on the same instance, and the console is unaffected, so it appears specific to the REST gateway path (possibly since the connectRPC migration, #10145). Happy to take a swing at a fix PR if useful.