feat(profiler/behave_shell): emit temporal.escalation_pattern

Bin commands into non-overlapping windows of width
max(ESCALATION_WINDOW_MIN_S, duration_s / ESCALATION_WINDOW_TARGET).
CV of per-window counts + zero-window fraction classify bursty /
sustained / erratic. v0.1; corpus re-tune deferred.

tests/profiler/behave_shell/test_temporal_escalation_pattern.py

@@ -0,0 +1,74 @@
+"""Step E.2: ``temporal.escalation_pattern``."""
+from __future__ import annotations
+
+from decnet.profiler.behave_shell import extract_session
+from decnet.profiler.behave_shell._parse import AsciinemaEvent
+
+
+PRIMITIVE = "temporal.escalation_pattern"
+
+
+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 _commands_at(starts: list[float]) -> list[AsciinemaEvent]:
+    events: list[AsciinemaEvent] = []
+    for s in starts:
+        events.append((s, "i", "x\r"))
+    return events
+
+
+def test_no_commands_no_emission() -> None:
+    out = list(extract_session([(0.0, "i", "a"), (10.0, "i", "b")], sid="esc-empty"))
+    assert [o for o in out if o.primitive == PRIMITIVE] == []
+
+
+def test_uniform_pace_emits_sustained() -> None:
+    """Even spacing across a long session → low CV → sustained."""
+    starts = [i * 12.0 for i in range(15)]  # 15 cmds over 168s, 10 windows
+    out = list(extract_session(_commands_at(starts), sid="esc-sus"))
+    obs = _of(out, PRIMITIVE)
+    assert obs.value == "sustained"
+
+
+def test_silent_periods_with_spikes_emit_bursty() -> None:
+    """Five tight bursts at session start, long silence, five at end."""
+    starts = [0.0, 0.5, 1.0, 1.5, 2.0,                 # spike 1
+              200.0, 200.5, 201.0, 201.5, 202.0]        # spike 2 after silence
+    out = list(extract_session(_commands_at(starts), sid="esc-burst"))
+    obs = _of(out, PRIMITIVE)
+    assert obs.value == "bursty"
+
+
+def test_variable_no_silence_emits_erratic() -> None:
+    """Variable rate but every window populated → CV in (0.5, 1.0), zero_frac=0 → erratic."""
+    # Last event at 120s so width = 12.0, n_windows = 10, bins [0,12), ..., [108,120).
+    # Each window populated; counts skewed enough to push CV above 0.5 but
+    # zero_frac stays at 0 so it can't qualify as bursty.
+    starts = [
+        0.0,                              # window 0 [0,12):       1
+        13.0, 15.0,                       # window 1 [12,24):      2
+        25.0,                             # window 2 [24,36):      1
+        37.0, 38.0, 39.0, 40.0, 41.0,     # window 3 [36,48):      5
+        50.0,                             # window 4 [48,60):      1
+        62.0, 64.0,                       # window 5 [60,72):      2
+        73.0,                             # window 6 [72,84):      1
+        86.0, 87.0, 88.0, 89.0, 90.0,     # window 7 [84,96):      5
+        100.0,                            # window 8 [96,108):     1
+        115.0, 120.0,                     # window 9 [108,120]:    2
+    ]
+    out = list(extract_session(_commands_at(starts), sid="esc-err"))
+    obs = _of(out, PRIMITIVE)
+    assert obs.value == "erratic"
+
+
+def test_short_session_low_confidence() -> None:
+    """Below the sample-size floor — confidence drops."""
+    short = list(extract_session(_commands_at([0.0, 1.0, 2.0]), sid="esc-short"))
+    full = list(extract_session(_commands_at([i * 12.0 for i in range(15)]), sid="esc-full"))
+    s = _of(short, PRIMITIVE)
+    f = _of(full, PRIMITIVE)
+    assert s.confidence < f.confidence