Add a team-card Lab 0 to the Cloud course

[sijie]

Why

The hackathon environments are created for each team, and teams are given access to the environment sheet that the organizers keep. Each team builds its own team card from its row: the addresses of a Kafka cluster, a SQL workspace and an agent workspace, plus an API key the team creates. The existing Lab 0 assumes an instance of your own, snctl lookups, and a topic you create. Teams in a created environment need a Lab 0 that creates nothing but a key.

What changed

• New page labs/cloud/00-set-up-team-card.md, "Lab 0: Set up from a team card". Step 2 maps six columns of the team row to .env lines, gives the console steps for creating an API key for the team service account, and shows a finished card with placeholders. Step 3 loads the login stream once for the team and runs the doctor. No snctl. The page keeps the step numbers of 00-set-up.md, so every existing "Lab 0, step 2/3" reference holds for both pages.
• labs/cloud/00-set-up.md and Labs 1 to 4 are unchanged. Troubleshooting has one changed row: with a team card, a rejected key is replaced by creating a new one.
• Pointers: the three READMEs, .env.cloud.example, and docs/before-you-arrive.md, where step 4 now tells teams in a created environment to skip it and create nothing in the console.
• Tutor: before Lab 0 of the Cloud course it asks whether the team has a row in the environment sheet, unless the learner said, and uses the matching page. docs/tutor.md has the same menu wording.
• Linter: scripts/check-labs.sh accepts a page the tutor names with its course folder (labs/cloud/<page>) and checks that it exists there, with a test.

What was run

• scripts/tests/run.sh (28 pass; the new test failed before the rule existed), scripts/check-labs.sh, and shellcheck.
• The other suites: CLI 151, Local 44, Python 224, TypeScript 240 and the typecheck.
• The page against a test instance on StreamNative Cloud, with the seven lines of step 2 filled in: every step and check on the Python path; the doctor and the seeder on the TypeScript path and with the commands of the CLI column. The topic was loaded already, so the seeder printed its "already holds" line.
• The tutor, one fresh-agent run per case. On the final wording: a team with a row in the sheet, and Cloud without saying. On the first wording: Cloud resuming at Lab 2, and Local from Lab 0.

Not run

• Reading the values from an environment sheet, and creating the API key. Its steps follow the labels of the console as of 3 October 2026 and were not clicked through; the key used in the walk was an existing one.
• The seeder on an empty topic from this page.
• An environment the organizers created.

Before the event

• The page names a SQL Database column that the environment sheet does not have yet.
• Participant logins must be able to create an API key for the service account of their team, and that one key has to be accepted by both the Kafka cluster and the agent workspace.