feat(profiler/behave_shell): G.8 emotional_valence.frustration_venting

Binary read of ctx.obscenity_hits (G.0 lexical counter):
* detected — obscenity_hits ≥ 1
* none     — zero hits

Skip below FRUST_VENT_MIN_TYPED_CHARS (30). Confidence hard-capped at
0.5: 0.40 when detected, 0.50 only when cleanly absent over ≥ 200
typed letters, 0.30 otherwise.

tests/profiler/behave_shell/test_emotional_valence_frustration_venting.py

@@ -0,0 +1,52 @@
+"""Step G.8: ``emotional_valence.frustration_venting`` ∈ {none, detected}.
+
+Hard 0.5 confidence cap.
+"""
+from __future__ import annotations
+
+from decnet.profiler.behave_shell import extract_session
+from decnet.profiler.behave_shell._parse import AsciinemaEvent
+
+
+PRIMITIVE = "emotional_valence.frustration_venting"
+
+
+def _of(observations: list, primitive: str):
+    obs = [o for o in observations if o.primitive == primitive]
+    assert len(obs) == 1, f"expected exactly one {primitive}, got {len(obs)}"
+    return obs[0]
+
+
+def _typed(text: str, t0: float = 0.0, dt: float = 0.05) -> list[AsciinemaEvent]:
+    return [(t0 + i * dt, "i", c) for i, c in enumerate(text)]
+
+
+def test_too_little_text_no_emission() -> None:
+    out = list(extract_session(_typed("hi"), sid="g8-thin"))
+    assert [o for o in out if o.primitive == PRIMITIVE] == []
+
+
+def test_detected_when_obscenity_present() -> None:
+    text = "hostname date hostname date oh fuck this is broken really "
+    obs = _of(list(extract_session(_typed(text), sid="g8-yes")), PRIMITIVE)
+    assert obs.value == "detected"
+    assert obs.confidence == 0.40
+
+
+def test_none_when_clean() -> None:
+    text = "hostname date hostname date hostname date hostname date "
+    obs = _of(list(extract_session(_typed(text), sid="g8-no")), PRIMITIVE)
+    assert obs.value == "none"
+
+
+def test_high_confidence_when_long_clean() -> None:
+    text = "hostname date " * 30
+    obs = _of(list(extract_session(_typed(text), sid="g8-long")), PRIMITIVE)
+    assert obs.value == "none"
+    assert obs.confidence == 0.50
+
+
+def test_cap_never_exceeded() -> None:
+    text = "fuck shit damn " * 30
+    obs = _of(list(extract_session(_typed(text), sid="g8-cap")), PRIMITIVE)
+    assert obs.confidence <= 0.50