docs: close the local Console login loop

[convee]

Summary

• put the Console URL, forwarding command, local token command, and paste target together in the README quickstart path
• print the same login instructions after quickstart/smoke and when starting the Console forward
• warn that the local development token is administrator-equivalent
• add a documentation regression test so the login loop cannot silently become incomplete

Validation

• manually signed into the real local Console in Chrome and inspected Sandbox, tenant, and template views
• verified health, node resources, Runtime/Workspace state, fail-closed template behavior, and logout/session clearing
• restored the original local token after the temporary login test
• make verify: 834 tests plus manifests, Helm, Console build, wheel, and CLI entrypoints passed in 87s
• make smoke-local: gVisor/runtime/persistence/fail-closed/metrics checks passed