fix(dashboard): paginate CEO dashboard ticket fetch to respect API cap

The CEO dashboard requested /api/tickets?page_size=500, but the API caps
page_size at 200 (le=200 in app/routers/tickets.py), so the request
returned 422 and every KPI/chart rendered zeros.

- ceo.html: fetch all tickets by looping pages of page_size=200 until
  total items are collected (with a safety bound), keeping KPIs accurate
  as volume grows past 200.
- tests: add test suite anchoring the pagination contract — page_size=500
  returns 422, page_size=200 returns items/total/page/page_size, and a
  page loop collects every ticket without duplicates.
- pyproject: enable pytest-asyncio auto mode and tests/ discovery.
- .gitignore: un-ignore committed tests/test_*.py.

tests/conftest.py

@@ -0,0 +1,66 @@
+"""Shared fixtures for the Denya OneCare test suite.
+
+Sets DATABASE_URL to an isolated temp SQLite file BEFORE importing any app
+module (the engine is created at import time), then provisions tables and
+seed data per test.
+"""
+
+from __future__ import annotations
+
+import os
+import tempfile
+from pathlib import Path
+
+_TMP_DIR = tempfile.mkdtemp(prefix="denya-test-")
+os.environ["DATABASE_URL"] = f"sqlite+aiosqlite:///{_TMP_DIR}/test.db"
+
+import pytest_asyncio
+from httpx import ASGITransport, AsyncClient
+
+from app.core.database import Base, async_session_factory, engine
+from app.main import app
+from app.models.ticket import Ticket
+from app.services.seed import seed_categories, seed_units, seed_users
+
+
+@pytest_asyncio.fixture
+async def client():
+    """Async test client with a fresh, seeded database per test."""
+    async with engine.begin() as conn:
+        await conn.run_sync(Base.metadata.create_all)
+    async with async_session_factory() as session:
+        await seed_users(session)
+        await session.commit()
+        # json_path=None → built-in fallback units (apartment_mapping.json is not committed)
+        await seed_units(session, json_path=None)
+        await session.commit()
+        await seed_categories(session)
+        await session.commit()
+
+    transport = ASGITransport(app=app)
+    async with AsyncClient(transport=transport, base_url="http://test") as c:
+        yield c
+
+    async with engine.begin() as conn:
+        await conn.run_sync(Base.metadata.drop_all)
+
+
+@pytest_asyncio.fixture
+async def seed_tickets():
+    """Insert `n` tickets directly into the DB; returns the count inserted."""
+
+    async def _seed(n: int) -> int:
+        async with async_session_factory() as session:
+            for i in range(n):
+                session.add(
+                    Ticket(
+                        ticket_number=f"PAV-TEST-{i:05d}",
+                        status="Logged",
+                        priority="medium",
+                        description=f"Test ticket {i}",
+                    )
+                )
+            await session.commit()
+        return n
+
+    return _seed