chore: add FIREFOX_EXTENSION_ID to extension workflow environment variables

[SuperCoolPencil]

Greptile Summary

Adds FIREFOX_EXTENSION_ID: surge@surge-downloader.com to the Submit to AMO step's environment variables in the extension workflow. Firefox extension IDs are public identifiers (visible in the manifest and on AMO), so hardcoding the value directly is appropriate here rather than using a secret.

Confidence Score: 5/5

Safe to merge — small, focused change with no correctness or security concerns.

The change is minimal and correct: it adds the required extension ID env var for wxt's AMO submission. The value is a public identifier, not a secret, so inline hardcoding is fine.

No files require special attention.

Important Files Changed

Filename	Overview
.github/workflows/extension.yml	Adds FIREFOX_EXTENSION_ID as a plaintext env var to the AMO submission step; value is a public extension identifier, not sensitive

_{Reviews (1): Last reviewed commit: "chore: add FIREFOX_EXTENSION_ID to exten..." | Re-trigger Greptile}