lith/deploy.fish: ship DO Spaces creds for notepat build stream
Decrypt aesthetic-computer-vault/spaces/.env.gpg during deploy,
scp the plaintext to /tmp/notepat-spaces.env on lith, source it for
just the build command, and remove. Keeps S3 keys off
/opt/ac/system/.env while still letting --sync-spaces push the
versioned amxd + latest.json to s3://assets-aesthetic-computer/m4l/
notepat.com/ on every deploy that triggered a rebuild.
Falls back to a build-without-sync (with a yellow warning) when the
vault file is absent or GPG can't decrypt without a passphrase
prompt — so deploys can still run in contexts where Spaces uploads
aren't required.