feat(m2): add silence flags at the 14, 7 and 10 day thresholds

Iron Law deviation, stated rather than hidden: these tests passed on the
first run. The silence computation landed in 4669cc3 because neste_frist is
one of Step 17's four cached keys and is derived from the same thresholds --
the plan entangles the two steps, so the code could not be written in the
order the steps are numbered. What this file adds is the boundary evidence:
13/14/15, 6/7/8, 9/10/11, an autoreply that must not move the clock, and the
H9 distinction between no inbound RECORDED and no inbound existing.

Co-Authored-By: Claude <claude-opus-5>

tests/test_sak_status_silence.py

@@ -0,0 +1,170 @@
+"""The three silence thresholds, measured against an injected clock (Step 18).
+
+build-brief 6 gives three rules and three numbers: 14 days in `sendt`, 7 in
+`dialog` when the other party owes the reply, 10 after an interview that has
+produced no outcome. Numbers in prose are easy to agree with and easy to be
+one day out on, so every one of them is tested on both sides of its boundary
+and on the boundary itself. A rule tested only in the middle of its range is a
+rule whose off-by-one nobody would notice.
+
+Two rules are not about arithmetic at all.
+
+`bekreftelse_mottatt` does not reset the clock. An automated receipt is not
+the employer making contact, and a machine that treated it as contact would
+quietly hide the case the operator most needs to see. The transition table
+leaves it out of `INNKOMMENDE`, and the boundary cases here are what makes
+that a fact.
+
+"No inbound recorded" is not "no inbound exists" (risk H9). With the mail
+server deferred nothing ingests replies, so an empty inbound history says
+something about this log and nothing about the world. The result carries that
+distinction in words, and `dagens` reads it from there rather than presenting
+every sent case as gone quiet.
+
+Cases here are built with `make_case` rather than from the fixture corpus:
+the corpus arrives in Step 19, and a test that needs a fixture from a later
+step cannot run when its own step is executed.
+
+Style note: this file follows tests/test_sak_status_transitions.py.
+"""
+
+import datetime
+
+import pytest
+
+from helpers import workspace as workspace_helper
+
+import sak_status
+
+TODAY = workspace_helper.FROZEN_TODAY
+
+
+def hendelse(navn, days_ago):
+    return workspace_helper.event(navn, days_ago=days_ago)
+
+
+def beslutning_ja(days_ago):
+    moment = workspace_helper.FROZEN_NOON - datetime.timedelta(days=days_ago)
+    return {"ts": moment.isoformat(), "type": "beslutning", "beslutning": "ja"}
+
+
+def sendt_for(dager, med_bekreftelse=False):
+    """A case whose application went out ``dager`` days ago and got no reply."""
+    logg = [hendelse("opprettet", dager + 2), beslutning_ja(dager + 1),
+            hendelse("soknad_sendt", dager)]
+    if med_bekreftelse:
+        # One day after the send, and it must not move the clock.
+        logg.append(hendelse("bekreftelse_mottatt", dager - 1))
+    return logg
+
+
+def dialog_med_dem_skyldig(siden):
+    """`dialog`, the other party owing, their last message ``siden`` days ago."""
+    return [
+        hendelse("opprettet", siden + 20), beslutning_ja(siden + 19),
+        hendelse("soknad_sendt", siden + 10),
+        hendelse("henvendelse_mottatt", siden),
+        hendelse("svar_sendt", siden - 1),
+    ]
+
+
+def intervju_holdt_for(dager):
+    return [
+        hendelse("opprettet", dager + 20), beslutning_ja(dager + 19),
+        hendelse("soknad_sendt", dager + 10),
+        hendelse("intervju_avtalt", dager + 5),
+        hendelse("intervju_gjennomfort", dager),
+    ]
+
+
+@pytest.mark.parametrize("dager,flagget", [(13, False), (14, True), (15, True)])
+def test_the_sendt_threshold_is_exactly_fourteen_days(dager, flagget):
+    resultat = sak_status.avgjor(sendt_for(dager), TODAY)
+    assert resultat["status"] == "sendt"
+    assert ("sendt_14" in resultat["flagg"]) is flagget
+
+
+@pytest.mark.parametrize("dager,flagget", [(13, False), (14, True), (15, True)])
+def test_an_automated_receipt_does_not_reset_the_sendt_clock(dager, flagget):
+    med = sak_status.avgjor(sendt_for(dager, med_bekreftelse=True), TODAY)
+    assert ("sendt_14" in med["flagg"]) is flagget, (
+        "bekreftelse_mottatt moved the clock; an autoreply is not contact"
+    )
+
+
+@pytest.mark.parametrize("dager,flagget", [(6, False), (7, True), (8, True)])
+def test_the_dialog_threshold_is_exactly_seven_days(dager, flagget):
+    resultat = sak_status.avgjor(dialog_med_dem_skyldig(dager), TODAY)
+    assert resultat["status"] == "dialog" and resultat["ventende_part"] == "dem"
+    assert ("dialog_7" in resultat["flagg"]) is flagget
+
+
+@pytest.mark.parametrize("dager,flagget", [(9, False), (10, True), (11, True)])
+def test_the_interview_threshold_is_exactly_ten_days(dager, flagget):
+    resultat = sak_status.avgjor(intervju_holdt_for(dager), TODAY)
+    assert resultat["status"] == "intervju"
+    assert ("intervju_10" in resultat["flagg"]) is flagget
+
+
+def test_a_dialog_where_i_owe_the_reply_is_never_flagged():
+    logg = [
+        hendelse("opprettet", 60), beslutning_ja(59), hendelse("soknad_sendt", 50),
+        hendelse("henvendelse_mottatt", 30),
+    ]
+    resultat = sak_status.avgjor(logg, TODAY)
+    assert resultat["ventende_part"] == "meg"
+    assert resultat["flagg"] == [], (
+        "thirty days of my own silence is a to-do, not the employer going quiet"
+    )
+
+
+@pytest.mark.parametrize("slutt", ("avslag", "trukket"))
+def test_terminal_states_are_never_flagged(slutt):
+    logg = sendt_for(60) + [hendelse(slutt, 50)]
+    resultat = sak_status.avgjor(logg, TODAY)
+    assert resultat["status"] == slutt
+    assert resultat["flagg"] == []
+    assert resultat["neste_frist"] is None
+
+
+def test_an_interview_with_an_outcome_stops_the_ten_day_clock():
+    logg = intervju_holdt_for(30) + [hendelse("tilbud_mottatt", 2)]
+    resultat = sak_status.avgjor(logg, TODAY)
+    assert resultat["status"] == "tilbud"
+    assert resultat["flagg"] == []
+
+
+def test_two_rules_at_once_produce_both_flags_in_a_stable_order():
+    logg = [
+        hendelse("opprettet", 60), beslutning_ja(59), hendelse("soknad_sendt", 50),
+        hendelse("intervju_avtalt", 30),
+        hendelse("intervju_gjennomfort", 20),
+        hendelse("henvendelse_mottatt", 12),
+        hendelse("svar_sendt", 11),
+    ]
+    resultat = sak_status.avgjor(logg, TODAY)
+    assert resultat["status"] == "dialog" and resultat["ventende_part"] == "dem"
+    assert resultat["flagg"] == ["dialog_7", "intervju_10"], (
+        "flags must come out in FLAGG order, never in the order the rules fired"
+    )
+    # The nearer of the two deadlines is the one the daily view has to show.
+    assert resultat["neste_frist"] == "2026-09-05"
+
+
+def test_no_inbound_recorded_is_reported_as_such_and_not_as_bare_silence():
+    resultat = sak_status.avgjor(sendt_for(20, med_bekreftelse=True), TODAY)
+    innkommende = resultat["innkommende"]
+    assert innkommende["registrert"] is False
+    assert innkommende["sist"] is None
+    assert "registrert" in innkommende["merknad"], (
+        "the case is flagged on an empty inbound history, and with the mail "
+        "server deferred that has to be said out loud (risk H9)"
+    )
+    assert "sendt_14" in resultat["flagg"]
+
+
+def test_a_recorded_inbound_carries_its_date_and_no_caveat():
+    resultat = sak_status.avgjor(dialog_med_dem_skyldig(9), TODAY)
+    assert resultat["innkommende"] == {
+        "registrert": True, "sist": "2026-09-06", "merknad": None,
+    }