Hide action fields for record-only automation sources

Found while checking Task 12270's UI. A record-only When source — Sentry, or a webhook whose Payload is "Incident" — never files a task (it only records incidents in its target project), yet the automation editor still requires and shows the Action section (persona, body template, title template) and the "Run now" button. Suggestions: 1. When the When source records only, hide or collapse the Action section and stop requiring an action on create; keep Target as "the project incidents are recorded in" with that label. 2. Hide or disable "Run now" for a record-only automation (nothing would run). 3. Rename the Target section's hint for record-only sources to "Records into" so it reads as the incident's project, not a filing target. Out of scope: changing how incidents are recorded; the incident → task automations (`incident`/`deploy_failed`/`health_breach` kinds). Done means: - Creating a Sentry automation in the console needs no Action fields; the API accepts it. - A record-only automation shows no Run now. - Existing event and schedule automations are unchanged (their tests stay green).

Record-only sources (Sentry, Incident webhook): no Action/picker/Run now/Test, Target "Records into" one project; API accepts no-action create, 409 on Run now. Quick gate + changed-area tests green; visual check done. PR #7635 queued. Memory: none applied.