feat(infra): add sweep coordinator, structured logging, test suite, and README

Sweep coordinator (Step 16):
- SweepCoordinator runs all 8 agents in parallel with 60s per-agent / 300s total timeout
- Aggregates findings, actions, errors into SweepCoordinatorResult
- Registered in FastAPI lifespan; triggered via POST /sweep

Structured logging (Step 18):
- logging_utils/structured.py: JSONFormatter emitting ts/level/logger/msg + custom fields
- log_directive_event() for structured directive lifecycle logging
- push_to_loki() async Loki push (graceful no-op if LOKI_URL unset)
- configure_logging() replaces root handler at startup

Tests (Steps 17+19):
- conftest.py: mock_odoo, mock_pool, mock_llm fixtures
- test_tool_validator.py: 9 tests covering validation, coercion, hallucination stripping
- test_llm_router.py: 6 tests covering local/cloud/hybrid modes and HIPAA enforcement
- test_peer_bus.py: 6 tests covering registration, timeout, depth, circular detection
- test_finance_agent.py: 10 tests covering all 6 steps + sweep + peer request
- test_memory_manager.py: 3 tests covering context build + hard cap enforcement
- test_dispatch_router.py: 3 tests covering dispatch, rate limit, health endpoint
- test_odoo_client.py: 4 tests covering search_read, write result, unlink warning
- test_e2e_dispatch.py: 2 E2E tests - full dispatch cycle + peer bus communication

README (Step 20): architecture diagram, privacy modes, quick start, env vars, structure

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

pytest.ini

@@ -0,0 +1,6 @@
+[pytest]
+asyncio_mode = auto
+testpaths = tests
+python_files = test_*.py
+python_classes = Test
+python_functions = test_