fix(firestore-send-email): kit/extension parity – kit uninstall leaves the function running or its secrets behind #3297

firestore-send-email kit/extension parity. Priority: medium. Uninstalling a kit set up the way the README describes leaves the function running and still sending mail. A successful uninstall also leaves the instance's secrets behind.

Difference

• Extension: deleting the instance removes the function, the service account, its IAM bindings and its managed secrets.
• Kit (firebase functions:kits:uninstall --instance <id>, firebase-tools 15.31.0):
  • Plain .env (the README's Usage layout): the command exits 0 and removes the instance from firebase.json, but deletes nothing. It warns only that the config folder "still contains files (.env)". The function stays deployed and keeps processing the mail collection.
  • Any other .env.<x> file in the folder (for example .env.bak): the command fails with Instance at … contains no .env file for current project.
  • With .env.<projectId>: the function and service account are deleted, but the four kit-<id>-* secrets stay in Secret Manager (one holds the SMTP password), along with four deleted:serviceAccount:… IAM bindings.

Reproduced

• Plain .env: uninstall exited 0, the instance left firebase.json, and kit-sepeu-processQueue stayed ACTIVE.
• With .env.corie-testing: the function and service account were deleted. kit-sepmig2-{SMTP_PASSWORD,CLIENT_ID,CLIENT_SECRET,REFRESH_TOKEN} and four dangling project IAM bindings remained.
• Extension: deleting the instance left no function, service account or IAM binding.

Code

• Kit README tells users to configure with .env: README.md#L49, #L85-L90
• The behaviour itself is in firebase-tools commands/functions-kits-uninstall.js (only .env.<project> files are acted on; secrets are not deleted).

Resolution

Same as #3262 for delete-user-data:

• the CLI should also act on a plain .env, or refuse with a clear error;
• it should offer to delete the kit-<id>-* secrets.

Until then, the README should say to use .env.<projectId> and to delete the secrets by hand.