docs(ipc): mark step 6 (cache integration) complete

Author: wan9chi

docs/runner-task-ipc/plan.md

@@ -5,4 +5,4 @@
 3. **Extract artifact** — Pull `artifact.rs` out of fspy into a shared crate. Prerequisite for dylib embedding. ✅
 4. **JS bridge** — `vite_task_client_napi` (real impl) + `@voidzero-dev/vite-task-client` (JS wrapper with `fetchEnvs` logic). ✅
 5. **Runner integration** — Wire into `vite_task` spawn: start server per execution, embed/extract dylib, inject the IPC envs via `serve()`'s returned iterator. ✅
-6. **Cache integration** — Runner consumes the reported data (ignored inputs/outputs, requested envs, disable cache) and adjusts caching behavior.
+6. **Cache integration** — Runner consumes the reported data (ignored inputs/outputs, requested envs, disable cache) and adjusts caching behavior. ✅