feat(profiler/behave_shell): G.3 operational.cleanup_behavior

* thorough — ≥ CLEANUP_THOROUGH_MIN_DISTINCT (3) distinct
  cleanup-family hashes in tail-CLEANUP_TAIL_K (5).
* partial  — 1-2 distinct.
* none     — zero hits.

Adjacent to E.4's binary exit_behavior=cleanup; G.3 graduates the
intensity. Confidence 0.55 above 8 commands; 0.35 below.

decnet/profiler/behave_shell/_features/__init__.py

@@ -32,6 +32,7 @@ from decnet.profiler.behave_shell._features.environmental import (
     terminal_multiplexer,
 )
 from decnet.profiler.behave_shell._features.operational import (
+    cleanup_behavior,
     objective,
     opsec_discipline,
 )
@@ -87,4 +88,5 @@ FEATURES: tuple[FeatureFn, ...] = (
     numpad_usage,
     objective,
     opsec_discipline,
+    cleanup_behavior,
 )