[omar-sift]

Description

When an organization has the async-exports feature flag off, ExportData does not return a job_id. sift-cli export assumed a job ID was always present:

• export --no-wait printed Started export job with a blank ID, linked to /manage/jobs?jobId=, and exited 0.
• export without --no-wait tried to fetch the job and failed with failed to retrieve job by ID.

export now checks for an empty job_id before it polls or prints a job link. It prints an error, links to the Sift jobs page, and exits 1:

error: The server did not return a job ID

Tip: Check the jobs page in Sift: https://<app-uri>/manage/jobs

Without a configured app_uri, the tip points to sift-cli config update --app-uri, as the other export messages do.

• Add build_jobs_page_url for the jobs page link. build_jobs_url now builds on it.
• Add an Unreleased changelog entry for sift-cli. Scripts that relied on exit status 0 from export --no-wait now fail.

Verification

• cargo test -p sift_cli passes. New explore_url tests cover the jobs page link, jobId encoding, and a missing, empty, or slash-only app_uri.
• cargo fmt --check passes.
• Ran sift-cli export asset ... --no-wait and sift-cli export asset ... against a local server with async-exports=off. Both print the error above and exit 1.