feat(emailgen): Ollama-driven fake email worker for IMAP/POP3 deckies

Second orchestrator worker (decnet emailgen) that drips persona-driven,
threaded, multi-language fake emails into running mail deckies.  Personas
live on Topology.email_personas; topology-wide language_default falls
through to any persona that doesn't pin its own.  Em-dashes are
suppressed at the prompt layer by default and only lifted for personas
explicitly marked uses_llms_heavily — em-dashes are an LLM tell and a
flat corpus of em-dashed mail is a giveaway.

EML delivery writes into /var/spool/decnet-emails/<thread>/<msg>.eml on
the mail decky via docker exec; wiring the IMAP/POP3 templates to read
from that spool (replacing the hardcoded _BAIT_EMAILS) is the next step.

tests/orchestrator/emailgen/test_worker_integration.py

@@ -0,0 +1,136 @@
+"""End-to-end-ish: one emailgen tick against a real SQLite repo + FakeBus,
+with the Ollama + docker-exec subprocess stubbed."""
+from __future__ import annotations
+
+import json
+
+import pytest
+import pytest_asyncio
+
+from decnet.bus.fake import FakeBus
+from decnet.orchestrator.drivers import email as email_driver
+from decnet.orchestrator.emailgen import worker as eg_worker
+from decnet.orchestrator.emailgen.scheduler import EmailAction  # noqa: F401
+from decnet.web.db.models import Topology, TopologyDecky
+from decnet.web.db.sqlite.repository import SQLiteRepository
+
+
+_PERSONAS = [
+    {
+        "name": "John Smith",
+        "email": "john@corp.com",
+        "role": "COO",
+        "tone": "formal",
+        "mannerisms": ["uses 'Best regards'"],
+        "active_hours": "00:00-00:00",  # always-on so test is hour-independent
+    },
+    {
+        "name": "Sarah Johnson",
+        "email": "sarah@corp.com",
+        "role": "PM",
+        "tone": "direct",
+        "mannerisms": ["uses bullets"],
+        "active_hours": "00:00-00:00",
+    },
+]
+
+
+@pytest_asyncio.fixture
+async def repo(tmp_path):
+    r = SQLiteRepository(db_path=str(tmp_path / "decnet.db"))
+    await r.initialize()
+    yield r
+    await r.engine.dispose()
+
+
+@pytest_asyncio.fixture
+async def fake_bus():
+    bus = FakeBus()
+    await bus.connect()
+    try:
+        yield bus
+    finally:
+        await bus.close()
+
+
+async def _seed_mail_topology(repo: SQLiteRepository) -> str:
+    async with repo._session() as session:
+        topo = Topology(
+            name="t-mail",
+            config_snapshot="{}",
+            status="active",
+            email_personas=json.dumps(_PERSONAS),
+            language_default="en",
+        )
+        session.add(topo)
+        await session.commit()
+        await session.refresh(topo)
+        decky = TopologyDecky(
+            topology_id=topo.id,
+            name="mailhost",
+            services=json.dumps(["imap"]),
+            ip="10.0.0.10",
+            state="running",
+        )
+        session.add(decky)
+        await session.commit()
+        await session.refresh(decky)
+        return decky.uuid
+
+
+@pytest.mark.asyncio
+async def test_one_tick_records_and_publishes(repo, fake_bus, monkeypatch):
+    decky_uuid = await _seed_mail_topology(repo)
+
+    async def fake_run_capture(argv, *, stdin_data=None, timeout=8.0):
+        if argv[0] == "ollama":
+            return 0, "Subject: Hi\n\nBody here.\n", ""
+        return 0, "", ""
+
+    monkeypatch.setattr(email_driver, "_run_capture", fake_run_capture)
+
+    received: list = []
+
+    async def collect():
+        async with fake_bus.subscribe(f"orchestrator.email.{decky_uuid}") as sub:
+            async for ev in sub:
+                received.append(ev)
+                return
+
+    import asyncio
+    collector = asyncio.create_task(collect())
+    await asyncio.sleep(0)
+
+    driver = email_driver.EmailDriver()
+    await eg_worker._one_tick(repo, driver, fake_bus)
+    await asyncio.wait_for(collector, timeout=2.0)
+
+    rows = await repo.list_orchestrator_emails()
+    assert len(rows) == 1
+    row = rows[0]
+    assert row["success"] is True
+    assert row["mail_decky_uuid"] == decky_uuid
+    assert row["subject"] == "Hi"
+    assert row["language"] == "en"
+
+    assert len(received) == 1
+    assert received[0].topic == f"orchestrator.email.{decky_uuid}"
+    assert received[0].payload["kind"] == "email"
+    assert received[0].payload["success"] is True
+
+
+@pytest.mark.asyncio
+async def test_one_tick_noop_when_no_mail_decky(repo, fake_bus, monkeypatch):
+    called = False
+
+    async def fake_run_capture(argv, *, stdin_data=None, timeout=8.0):
+        nonlocal called
+        called = True
+        return 0, "Subject: x\n\nb\n", ""
+
+    monkeypatch.setattr(email_driver, "_run_capture", fake_run_capture)
+
+    driver = email_driver.EmailDriver()
+    await eg_worker._one_tick(repo, driver, fake_bus)
+    assert called is False
+    assert await repo.list_orchestrator_emails() == []