Reduce supported platform matrix

docs/internal/adapters.md

@@ -78,11 +78,10 @@ in-memory backend without changing package state.
 - Subprocess adapters persist stage logs/generated configs through stage-managed paths.
 - Shared subprocess execution keeps private lifecycle mechanics separate from
   Narratio's environment, diagnostics, redaction, and error policy. It starts
-  an owned process group on Linux/macOS or a
-  kill-on-close job object on Windows. Every terminal path disposes of that
-  owned tree before returning. After a natural leader exit, Unix checks for
-  remaining group members and uses bounded graceful then forceful termination;
-  Windows closes the job so kill-on-close applies. Cancellation, deadlines, and
+  an owned process group on Linux and macOS. Every terminal path disposes of
+  that owned tree before returning. After a natural leader exit, the runner checks
+  for remaining group members and uses bounded graceful then forceful termination.
+  Cancellation, deadlines, and
   diagnostic limits use the same terminal disposal path without losing their
   original result classification. Child environments contain only the execution
   baseline and adapter-specified values; configured credentials are explicit