feat: Phase 3 — web dashboard, testing, and CI/CD

- Remove multi-marketplace from Phase 3
- Add FastAPI web UI on port 8766 with basic auth
- Add 6 Jinja2 templates (dashboard, keywords, users, ads, stats)
- Add pytest test suite (45 tests, 49% coverage)
- Add GitHub Actions CI/CD workflow
- Update docker-compose.yml to expose web UI port
- Update Dockerfile to include tests

worker/tests/conftest.py

@@ -0,0 +1,84 @@
+"""Shared pytest fixtures for the willhaben-tracker test suite."""
+
+from datetime import datetime, timezone
+from unittest.mock import AsyncMock, MagicMock
+
+import pytest
+
+
+def pytest_configure(config):
+    """Enable asyncio auto mode for all async tests."""
+    config.addinivalue_line("markers", "asyncio: mark test as async")
+
+
+@pytest.fixture
+def mock_pool():
+    """Mock asyncpg.Pool with fetch/fetchrow/execute/fetchval methods."""
+    pool = MagicMock()
+    pool.fetch = AsyncMock(return_value=[])
+    pool.fetchrow = AsyncMock(return_value=None)
+    pool.execute = AsyncMock(return_value=None)
+    pool.fetchval = AsyncMock(return_value=None)
+    return pool
+
+
+@pytest.fixture
+def mock_bot():
+    """Mock ExtBot with send_message/send_photo methods."""
+    bot = MagicMock()
+    bot.send_message = AsyncMock(return_value=MagicMock(message_id=123))
+    bot.send_photo = AsyncMock(return_value=MagicMock(message_id=123))
+    return bot
+
+
+@pytest.fixture
+def sample_ad_data():
+    """Sample willhaben ad JSON dict matching the API response format."""
+    return {
+        "id": "12345678",
+        "description": "A used bicycle",
+        "attributes": {
+            "attribute": [
+                {"name": "HEADING", "values": ["Mountain Bike 2024"]},
+                {"name": "PRICE/AMOUNT", "values": ["250"]},
+                {"name": "LOCATION", "values": ["Vienna"]},
+                {"name": "POSTCODE", "values": ["1010"]},
+                {"name": "SEO_URL", "values": ["mountain-bike-2024/12345678"]},
+                {"name": "PUBLISHED_String", "values": ["2024-01-15T10:30:00Z"]},
+                {"name": "CHANGED_String", "values": ["2024-01-15T12:00:00Z"]},
+            ]
+        },
+        "advertImageList": {
+            "advertImage": [
+                {"referenceImageUrl": "https://img.willhaben.at/img123.jpg"}
+            ]
+        },
+    }
+
+
+@pytest.fixture
+def sample_fields():
+    """Sample extracted ad fields dict as returned by extract_ad_fields()."""
+    return {
+        "wh_ad_id": "12345678",
+        "title": "Mountain Bike 2024",
+        "price": 250.0,
+        "location": "Vienna",
+        "url": "https://www.willhaben.at/iad/mountain-bike-2024/12345678",
+        "published_at": datetime(2024, 1, 15, 10, 30, 0, tzinfo=timezone.utc),
+        "main_image_url": "https://img.willhaben.at/img123.jpg",
+        "postcode": "1010",
+        "modified_at": datetime(2024, 1, 15, 12, 0, 0, tzinfo=timezone.utc),
+    }
+
+
+@pytest.fixture
+def sample_kw_row():
+    """Sample keyword row dict with filter settings."""
+    return {
+        "id": "kw-uuid-123",
+        "keyword": "bike",
+        "price_min": None,
+        "price_max": None,
+        "allowed_postcodes": None,
+    }