The D-206 queue (#924) and D-203 cache (#917) were built but never connected to
the running app — the whole background tier was inert. This closes the loop:
submit -> Rayon -> cascade -> completion -> drain -> cache.
- gen_queue.rs: GenWorkItem::AnalyzeBody now carries enqueuer-resolved inputs
{ body_id, heightmap_path, sea_level, body_seed: SeedChain } (D-225 boundary —
run_work_item stays pure compute, no path/DB resolution). run_work_item runs
the real cascade: load heightmap.png -> downsample to GRID_W×GRID_H working
grid (D-202) -> run_layer1 -> BodyWorldState; load failure -> Failed.
GenCompletion::BodyAnalyzed carries the computed BodyWorldState.
- cascade.rs: CascadeSnapshot::into_body_world_state() conversion.
- plugin.rs (new): GenerationPlugin registers GenerationQueue +
BodyWorldStateCache and adds a PreInput drain system that inserts BodyAnalyzed
states into the cache (off the Rayon workers — a cheap channel drain, never
the ~45ms cascade). Wired into both the production and test app setups.
Tests run the real cascade on a tiny temp heightmap PNG (no committed fixture);
the plugin test proves the full submit->...->cache loop. The proxy (#969) is the
production submitter.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>