fix: clean up utcnow deprecation warnings, fix 12 failing tests, add CI/CD pipeline manifests

- Replace all datetime.utcnow() with datetime.now(tz=timezone.utc) across 8 files
- Fix 12 failing tests to match current implementation behavior
- Fix pytest_plugins in non-top-level conftest (moved to root conftest.py)
- Auto-fix 189 lint issues (import sorting, unused imports)
- Add CI/CD pipeline infrastructure (ARC, ArgoCD, Kargo manifests)
- Add values-beta.yaml and values-paper.yaml for staged deployments
- Update GitHub Actions workflow to use self-hosted-gremlin runners
- Add integration-test job to CI pipeline

Result: 1596 passed, 0 failed, 0 warnings

tests/test_macro_api.py

@@ -9,13 +9,13 @@ from __future__ import annotations
 
 import json
 from datetime import datetime, timezone
-from unittest.mock import AsyncMock, MagicMock, patch
+from unittest.mock import AsyncMock, patch
 from uuid import uuid4
 
 import pytest
 from httpx import ASGITransport, AsyncClient
 
-from services.api.app import _parse_jsonb, _row_to_dict, app
+from services.api.app import app
 
 # ---------------------------------------------------------------------------
 # Helpers
@@ -188,9 +188,9 @@ class TestMacroEventEndpoints:
         data = resp.json()
         assert data["id"] == event_id
         assert data["severity"] == "high"
-        assert "affected_companies" in data
-        assert len(data["affected_companies"]) == 1
-        assert data["affected_companies"][0]["ticker"] == "AAPL"
+        assert "impacts" in data
+        assert len(data["impacts"]) == 1
+        assert data["impacts"][0]["ticker"] == "AAPL"
 
     @pytest.mark.asyncio
     async def test_get_macro_event_not_found(self):
@@ -361,6 +361,8 @@ class TestMacroImpactsEndpoint:
         """GET /api/macro/impacts/{ticker} should return impact records."""
         impact_row = _make_impact_row(str(uuid4()))
         mock_pool = AsyncMock()
+        # fetchrow returns None (no exposure profile)
+        mock_pool.fetchrow = AsyncMock(return_value=None)
         mock_pool.fetch = AsyncMock(return_value=[impact_row])
 
         with patch("services.api.app.pool", mock_pool):
@@ -370,8 +372,9 @@ class TestMacroImpactsEndpoint:
 
         assert resp.status_code == 200
         data = resp.json()
-        assert isinstance(data, list)
-        assert len(data) == 1
-        assert data[0]["ticker"] == "AAPL"
-        assert data[0]["macro_impact_score"] == 0.45
-        assert data[0]["impact_direction"] == "negative"
+        assert data["exposure_profile"] is None
+        assert isinstance(data["impacts"], list)
+        assert len(data["impacts"]) == 1
+        assert data["impacts"][0]["ticker"] == "AAPL"
+        assert data["impacts"][0]["macro_impact_score"] == 0.45
+        assert data["impacts"][0]["impact_direction"] == "negative"