Status: IN
The architecture achieves complete duplicate prevention from external API boundary to internal storage through complementary forward-only mechanisms: idempotency keys extend forward-only semantics to the client boundary (making duplicate submissions return cached results permanently), while stratified dedup covers internal processing with accuracy adapted to cost (exact key-based at API boundaries, coordinated window-based at stream boundaries, probabilistic at crawl boundaries).
Client-facing idempotency and internal stratified dedup together cover the full duplicate prevention surface
Depends on (SL): idempotency-extends-forward-only-to-client-boundary, dedup-is-stratified-across-boundaries-and-accuracy-levels