@mytec: feat: Phase 3.0 Architecture Refactor ✅

Major refactoring of RFCP backend:
- Modular propagation models (8 models)
- SharedMemoryManager for terrain data
- ProcessPoolExecutor parallel processing
- WebSocket progress streaming
- Building filtering pipeline (351k → 15k)
- 82 unit tests

Performance: Standard preset 38s → 5s (7.6x speedup)

Known issue: Detailed preset timeout (fix in 3.1.0)

backend/tests/test_integration/test_engine.py

@@ -0,0 +1,115 @@
+"""
+Integration tests for the CoverageEngine orchestrator.
+
+Tests model selection, available models API, and the
+engine's coordination logic (without running actual
+coverage calculations, which require terrain data).
+"""
+
+import sys
+import os
+
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..', '..'))
+
+from app.core.engine import CoverageEngine, BandType, PresetType, CoverageSettings
+
+
+class TestEngineModelSelection:
+    def test_lte_urban_uses_cost231(self):
+        engine = CoverageEngine()
+        model = engine.select_model(BandType.LTE, "urban")
+        assert model.name == "COST-231-Hata"
+
+    def test_lte_suburban_uses_okumura(self):
+        engine = CoverageEngine()
+        model = engine.select_model(BandType.LTE, "suburban")
+        assert model.name == "Okumura-Hata"
+
+    def test_lte_open_uses_fspl(self):
+        engine = CoverageEngine()
+        model = engine.select_model(BandType.LTE, "open")
+        assert model.name == "Free-Space"
+
+    def test_uhf_urban_uses_okumura(self):
+        engine = CoverageEngine()
+        model = engine.select_model(BandType.UHF, "urban")
+        assert model.name == "Okumura-Hata"
+
+    def test_uhf_rural_uses_longley_rice(self):
+        engine = CoverageEngine()
+        model = engine.select_model(BandType.UHF, "rural")
+        assert model.name == "Longley-Rice"
+
+    def test_vhf_urban_uses_p1546(self):
+        engine = CoverageEngine()
+        model = engine.select_model(BandType.VHF, "urban")
+        assert model.name == "ITU-R-P.1546"
+
+    def test_vhf_rural_uses_longley_rice(self):
+        engine = CoverageEngine()
+        model = engine.select_model(BandType.VHF, "rural")
+        assert model.name == "Longley-Rice"
+
+    def test_unknown_band_falls_back(self):
+        engine = CoverageEngine()
+        model = engine.select_model(BandType.CUSTOM, "desert")
+        assert model is not None  # Should not crash
+
+
+class TestEngineModelsAPI:
+    def test_returns_dict(self):
+        engine = CoverageEngine()
+        models = engine.get_available_models()
+        assert isinstance(models, dict)
+        assert len(models) >= 5
+
+    def test_model_info_structure(self):
+        engine = CoverageEngine()
+        models = engine.get_available_models()
+        for name, info in models.items():
+            assert "frequency_range" in info
+            assert "distance_range" in info
+            assert "bands" in info
+            assert len(info["bands"]) > 0
+
+    def test_all_expected_models_present(self):
+        engine = CoverageEngine()
+        models = engine.get_available_models()
+        expected = {"COST-231-Hata", "Okumura-Hata", "Free-Space", "Longley-Rice", "ITU-R-P.1546"}
+        assert expected.issubset(set(models.keys()))
+
+
+class TestCoverageSettings:
+    def test_default_settings(self):
+        s = CoverageSettings()
+        assert s.radius == 10000
+        assert s.resolution == 200
+        assert s.preset == PresetType.STANDARD
+        assert s.band_type == BandType.LTE
+
+    def test_preset_values(self):
+        assert PresetType.FAST.value == "fast"
+        assert PresetType.STANDARD.value == "standard"
+        assert PresetType.DETAILED.value == "detailed"
+        assert PresetType.FULL.value == "full"
+
+    def test_band_type_values(self):
+        assert BandType.LTE.value == "lte"
+        assert BandType.UHF.value == "uhf"
+        assert BandType.VHF.value == "vhf"
+
+
+if __name__ == "__main__":
+    for cls_name, cls in [
+        ("ModelSelection", TestEngineModelSelection),
+        ("ModelsAPI", TestEngineModelsAPI),
+        ("CoverageSettings", TestCoverageSettings),
+    ]:
+        instance = cls()
+        for method_name in [m for m in dir(instance) if m.startswith("test_")]:
+            try:
+                getattr(instance, method_name)()
+                print(f"  PASS  {cls_name}.{method_name}")
+            except Exception as e:
+                print(f"  FAIL  {cls_name}.{method_name}: {e}")
+    print("\nAll tests completed.")