fix: resolve mypy errors, fix arxiv test session isolation, and add premerge script

- Remove unused type:ignore comment in scholars.py
- Fix 51 mypy errors across test files (Any return types, cast(), protocol stubs)
- Fix arxiv unit test failures caused by session isolation (patch_session_factory fixture)
- Fix integration test rate-limit bleed between search and create
- Add scripts/premerge.sh for local CI verification
- Add docs/website/.docusaurus/ to .gitignore

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tests/unit/services/domains/arxiv/conftest.py

@@ -0,0 +1,17 @@
+from __future__ import annotations
+
+import pytest
+from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker
+
+
+@pytest.fixture
+def patch_session_factory(db_session: AsyncSession, monkeypatch: pytest.MonkeyPatch):
+    """Patch get_session_factory in arxiv modules to use the test's DB engine.
+
+    Without this, the implementation creates its own engine via get_session_factory()
+    which may not share transaction visibility with the test's db_session fixture.
+    """
+    factory = async_sessionmaker(db_session.bind, expire_on_commit=False)
+    monkeypatch.setattr("app.services.arxiv.rate_limit.get_session_factory", lambda: factory)
+    monkeypatch.setattr("app.services.arxiv.cache.get_session_factory", lambda: factory)
+    return factory

tests/unit/services/domains/arxiv/test_client.py

@@ -147,8 +147,8 @@ async def test_client_coalesces_concurrent_identical_search_requests() -> None:
 async def test_client_logs_cache_hit_and_miss(
     db_session: AsyncSession,
     monkeypatch: pytest.MonkeyPatch,
+    patch_session_factory,
 ) -> None:
-    _ = db_session
     calls = {"count": 0}
     logged: list[dict[str, object]] = []
 

tests/unit/services/domains/arxiv/test_gateway.py

@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from types import SimpleNamespace
+from typing import Any
 
 import pytest
 
@@ -10,7 +10,9 @@ from app.services.arxiv.types import ArxivEntry, ArxivFeed, ArxivOpenSearchMeta
 from app.settings import settings
 
 
-def _item(*, title: str = "A Test Paper", scholar_label: str = "Ada Lovelace") -> SimpleNamespace:
+def _item(*, title: str = "A Test Paper", scholar_label: str = "Ada Lovelace") -> Any:
+    from types import SimpleNamespace
+
     return SimpleNamespace(title=title, scholar_label=scholar_label)
 
 
@@ -71,7 +73,7 @@ async def test_http_gateway_returns_none_when_disabled(monkeypatch: pytest.Monke
     fake_client = FakeClient()
     object.__setattr__(settings, "arxiv_enabled", False)
     try:
-        gateway = arxiv_gateway.HttpArxivGateway(client=fake_client)
+        gateway = arxiv_gateway.HttpArxivGateway(client=fake_client)  # type: ignore[arg-type]
         result = await gateway.discover_arxiv_id_for_publication(item=_item())
         assert result is None
         assert fake_client.calls == 0
@@ -102,7 +104,7 @@ async def test_http_gateway_uses_client_search_for_discovery() -> None:
             )
 
     fake_client = FakeClient()
-    gateway = arxiv_gateway.HttpArxivGateway(client=fake_client)
+    gateway = arxiv_gateway.HttpArxivGateway(client=fake_client)  # type: ignore[arg-type]
     result = await gateway.discover_arxiv_id_for_publication(
         item=_item(title="My Paper", scholar_label="Ada Lovelace"),
         request_email="user@example.com",

tests/unit/services/domains/arxiv/test_rate_limit.py

@@ -16,7 +16,7 @@ from app.settings import settings
 
 
 @pytest.mark.asyncio
-async def test_arxiv_rate_limit_respects_cooldown(db_session: AsyncSession) -> None:
+async def test_arxiv_rate_limit_respects_cooldown(db_session: AsyncSession, patch_session_factory) -> None:
     db_session.add(
         ArxivRuntimeState(
             state_key=ARXIV_RUNTIME_STATE_KEY,
@@ -37,7 +37,7 @@ async def test_arxiv_rate_limit_respects_cooldown(db_session: AsyncSession) -> N
 
 
 @pytest.mark.asyncio
-async def test_arxiv_rate_limit_persists_cooldown_after_429(db_session: AsyncSession) -> None:
+async def test_arxiv_rate_limit_persists_cooldown_after_429(db_session: AsyncSession, patch_session_factory) -> None:
     previous_interval = settings.arxiv_min_interval_seconds
     previous_cooldown = settings.arxiv_rate_limit_cooldown_seconds
     object.__setattr__(settings, "arxiv_min_interval_seconds", 0.0)
@@ -62,7 +62,7 @@ async def test_arxiv_rate_limit_persists_cooldown_after_429(db_session: AsyncSes
 
 
 @pytest.mark.asyncio
-async def test_arxiv_rate_limit_serializes_concurrent_calls(db_session: AsyncSession) -> None:
+async def test_arxiv_rate_limit_serializes_concurrent_calls(db_session: AsyncSession, patch_session_factory) -> None:
     previous_interval = settings.arxiv_min_interval_seconds
     previous_cooldown = settings.arxiv_rate_limit_cooldown_seconds
     object.__setattr__(settings, "arxiv_min_interval_seconds", 0.2)
@@ -90,6 +90,7 @@ async def test_arxiv_rate_limit_serializes_concurrent_calls(db_session: AsyncSes
 async def test_arxiv_rate_limit_logs_request_scheduled_and_completed(
     db_session: AsyncSession,
     monkeypatch: pytest.MonkeyPatch,
+    patch_session_factory,
 ) -> None:
     logged: list[dict[str, object]] = []
 
@@ -107,8 +108,8 @@ async def test_arxiv_rate_limit_logs_request_scheduled_and_completed(
 
     assert scheduled
     assert completed
-    assert float(scheduled[0]["wait_seconds"]) >= 0.0
-    assert int(completed[0]["status_code"]) == 200
+    assert float(str(scheduled[0]["wait_seconds"])) >= 0.0
+    assert int(str(completed[0]["status_code"])) == 200
     assert completed[0]["source_path"] == "search"
 
 
@@ -116,6 +117,7 @@ async def test_arxiv_rate_limit_logs_request_scheduled_and_completed(
 async def test_arxiv_rate_limit_logs_cooldown_activation(
     db_session: AsyncSession,
     monkeypatch: pytest.MonkeyPatch,
+    patch_session_factory,
 ) -> None:
     logged_warning: list[dict[str, object]] = []
     previous_interval = settings.arxiv_min_interval_seconds
@@ -140,11 +142,11 @@ async def test_arxiv_rate_limit_logs_cooldown_activation(
     cooldown_events = [entry for entry in logged_warning if entry.get("event") == "arxiv.cooldown_activated"]
     assert cooldown_events
     assert cooldown_events[0]["source_path"] == "lookup_ids"
-    assert float(cooldown_events[0]["cooldown_remaining_seconds"]) > 0.0
+    assert float(str(cooldown_events[0]["cooldown_remaining_seconds"])) > 0.0
 
 
 @pytest.mark.asyncio
-async def test_get_arxiv_cooldown_status_reads_active_cooldown(db_session: AsyncSession) -> None:
+async def test_get_arxiv_cooldown_status_reads_active_cooldown(db_session: AsyncSession, patch_session_factory) -> None:
     now_utc = datetime(2026, 2, 26, 13, 0, tzinfo=UTC)
     existing = await db_session.get(ArxivRuntimeState, ARXIV_RUNTIME_STATE_KEY)
     if existing is None: