feat: unified fiscal coverage - PIS/COFINS applicability + conditional RTC in one definition, one queue, one panel

- central/app/unified_fiscal_coverage.py: pure rules (PIS/COFINS NOT_APPLICABLE/REQUIRED/OPTIONAL/NEEDS_REVIEW, RTC only when the ERP switch is on)
- agent: read-only loader (unified_fiscal.py) replaces the legacy/expanded module; findings feed the single operational state, coverage and blocker queue
- hub: BLOCKED_FISCAL_DATA blockers (PIS/COFINS/RTC) share the queue; stale ones close on the next full pass; dashboard breakdown gains CEST/PIS/COFINS/RTC
- panel: legacy/expanded coverage block removed; discreet 'Reforma Tributaria: Ativa/Desativada'
- docs: unified_fiscal_completeness, pis_cofins_applicability, rtc_pis_cofins_model + official source manifests; read-only E2E script

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

agent/tests/conftest.py

@@ -1,3 +1,24 @@
 import sys
 from pathlib import Path
 sys.path.insert(0, str(Path(__file__).parents[1] / "src"))
+
+
+import pytest
+
+
+@pytest.fixture(autouse=True)
+def _no_real_firebird_for_unified_fiscal(monkeypatch, request):
+    """The unified fiscal assessment opens its own READ ONLY connection; unit tests have no Firebird, so it is neutral here unless a test opts in."""
+    if request.node.get_closest_marker("real_unified_fiscal"):
+        return
+    from gti_fiscal_agent import firebird_reader, unified_fiscal
+
+    class _Conn:
+        def close(self):
+            pass
+    monkeypatch.setattr(firebird_reader, "_connect", lambda env: _Conn())
+    monkeypatch.setattr(unified_fiscal, "assess_from_connection", lambda conn, company, **kw: {"context": {"rtc_enabled": False, "rtc_supported": False, "rtc_catalog_valid": False, "products_evaluated": 0}, "findings": {}})
+
+
+def pytest_configure(config):
+    config.addinivalue_line("markers", "real_unified_fiscal: use the real unified fiscal assessment (with a fake cursor) instead of the neutral stub")