Stop scheduled review storms on unchanged issues

A newly opened issue was reviewed nine times in about 12 hours even though only ClawSweeper-owned labels and durable-comment edits changed after the first review. The duplicate runs generated repeated contributor notifications and consumed review capacity for unchanged input.

Forwarded the claimed queue decision's source action into review preparation as a typed internal input, then classified scheduled hot intake and scheduled normal backfill as automatic while preserving explicit behavior for commands, webhooks, legacy dispatches, unknown actions, and missing actions.

• Prevents scheduled hot and normal queues from repeatedly reviewing unchanged issues after bot-owned activity.
• Reduces unnecessary GitHub Actions usage, model-review capacity, contributor notifications, and durable-comment churn.
• Keeps explicit reruns available for intentional fresh review while allowing scheduled lanes to reuse verified structural receipts.

• Added review-preparation coverage for scheduled actions, explicit actions, missing and unknown actions, legacy compatibility, and non-exact selection.
• Exercised runtime, workflow, scheduler, structural-cache, semantic-cache, content-cache, and scheduled-enqueue suites in the PR.
• Merged as commit 138ee2f after the fix, with a reporter note thanking the focused repair.