feat(profiler/behave_shell): G.4 operational.multi_actor_indicators

Compare median intra-command IATs of the two temporal halves of the
session. ≥ MULTI_ACTOR_HALF_MIN_COMMANDS (4) per half required;
relative delta > MULTI_ACTOR_HANDOFF_DELTA (0.5) → handoff_detected.

team_coordinated is Tier B (cross-session); never emitted from a
single session. Confidence 0.55 with both halves ≥ 8 commands; 0.40
otherwise.

tests/profiler/behave_shell/test_operational_multi_actor.py

@@ -0,0 +1,73 @@
+"""Step G.4: ``operational.multi_actor_indicators`` ∈ {solo, handoff_detected}.
+
+``team_coordinated`` is Tier B (cross-session) — never emitted here.
+"""
+from __future__ import annotations
+
+from decnet.profiler.behave_shell import extract_session
+from decnet.profiler.behave_shell._parse import AsciinemaEvent
+
+
+PRIMITIVE = "operational.multi_actor_indicators"
+
+
+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, dt: float = 0.05) -> list[AsciinemaEvent]:
+    return [(t0 + i * dt, "i", c) for i, c in enumerate(text)]
+
+
+def _cmd(token: str, t0: float, dt: float = 0.05) -> list[AsciinemaEvent]:
+    """Emit one command (no prompt — output unused for this primitive)."""
+    events = _typed(f"{token}\r", t0=t0, dt=dt)
+    return events
+
+
+def test_too_few_commands_no_emission() -> None:
+    events: list[AsciinemaEvent] = []
+    for i in range(5):
+        events += _cmd("ls", t0=float(i))
+    out = list(extract_session(events, sid="g4-thin"))
+    assert [o for o in out if o.primitive == PRIMITIVE] == []
+
+
+def test_solo_consistent_typing() -> None:
+    """Same dt across both halves → small delta → solo."""
+    events: list[AsciinemaEvent] = []
+    for i in range(10):
+        events += _cmd("hostname", t0=float(i * 2), dt=0.10)
+    obs = _of(list(extract_session(events, sid="g4-solo")), PRIMITIVE)
+    assert obs.value == "solo"
+
+
+def test_handoff_detected_speed_jump() -> None:
+    """First half slow typing (dt=0.20), second half fast (dt=0.05)."""
+    events: list[AsciinemaEvent] = []
+    for i in range(8):
+        events += _cmd("hostname", t0=float(i * 2), dt=0.20)
+    for i in range(8):
+        events += _cmd("hostname", t0=float(20 + i * 2), dt=0.05)
+    obs = _of(list(extract_session(events, sid="g4-handoff")), PRIMITIVE)
+    assert obs.value == "handoff_detected"
+
+
+def test_team_coordinated_never_emitted() -> None:
+    """Tier B value must never appear, regardless of input."""
+    events: list[AsciinemaEvent] = []
+    for i in range(20):
+        dt = 0.10 + (0.20 if i % 2 else 0.0)
+        events += _cmd("hostname", t0=float(i * 2), dt=dt)
+    obs = _of(list(extract_session(events, sid="g4-no-team")), PRIMITIVE)
+    assert obs.value in ("solo", "handoff_detected")
+
+
+def test_high_count_raises_confidence() -> None:
+    events: list[AsciinemaEvent] = []
+    for i in range(20):
+        events += _cmd("hostname", t0=float(i * 2), dt=0.10)
+    obs = _of(list(extract_session(events, sid="g4-conf")), PRIMITIVE)
+    assert obs.confidence == 0.55