feat(profiler/behave_shell): emit cognitive.error_resilience.frustration_typing

Compares median within-command IAT for commands following an errored
command vs commands following a successful one. Relative absolute delta
buckets to low / moderate / high. Skips when either group is empty
(no errors, or no clean baseline). v0.1; D.8 re-tunes.

decnet/profiler/behave_shell/_features/__init__.py

@@ -14,6 +14,7 @@ from decnet.profiler.behave_shell._ctx import SessionContext
 from decnet.profiler.behave_shell._features.cognitive import (
     cognitive_load,
     command_branch_diversity,
+    error_resilience_frustration_typing,
     error_resilience_retry_tactic,
     exploration_style,
     feedback_loop_engagement,
@@ -55,4 +56,5 @@ FEATURES: tuple[FeatureFn, ...] = (
     planning_depth,
     tool_vocabulary,
     error_resilience_retry_tactic,
+    error_resilience_frustration_typing,
 )