@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_models/test_cost231.py

@@ -0,0 +1,90 @@
+"""
+Unit tests for COST-231 Hata and COST-231 Walfisch-Ikegami models.
+"""
+
+import sys
+import os
+
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..', '..'))
+
+from app.propagation.base import PropagationInput
+from app.propagation.cost231_hata import Cost231HataModel
+from app.propagation.cost231_wi import Cost231WIModel
+
+
+def make_input(**kwargs) -> PropagationInput:
+    defaults = {
+        "frequency_mhz": 1800,
+        "distance_m": 5000,
+        "tx_height_m": 30,
+        "rx_height_m": 1.5,
+        "environment": "urban",
+    }
+    defaults.update(kwargs)
+    return PropagationInput(**defaults)
+
+
+class TestCost231Hata:
+    def test_typical_range(self):
+        model = Cost231HataModel()
+        out = model.calculate(make_input())
+        assert 130 < out.path_loss_db < 170
+
+    def test_model_name(self):
+        model = Cost231HataModel()
+        assert model.name == "COST-231-Hata"
+
+    def test_frequency_range(self):
+        model = Cost231HataModel()
+        assert model.is_valid_for(make_input(frequency_mhz=1500))
+        assert model.is_valid_for(make_input(frequency_mhz=2000))
+        assert not model.is_valid_for(make_input(frequency_mhz=900))
+
+    def test_distance_increases_loss(self):
+        model = Cost231HataModel()
+        loss_2 = model.calculate(make_input(distance_m=2000)).path_loss_db
+        loss_10 = model.calculate(make_input(distance_m=10000)).path_loss_db
+        assert loss_10 > loss_2
+
+    def test_urban_vs_suburban(self):
+        model = Cost231HataModel()
+        urban = model.calculate(make_input(environment="urban")).path_loss_db
+        suburban = model.calculate(make_input(environment="suburban")).path_loss_db
+        assert suburban < urban
+
+
+class TestCost231WI:
+    def test_typical_range(self):
+        model = Cost231WIModel()
+        out = model.calculate(make_input(distance_m=500))
+        assert 80 < out.path_loss_db < 160
+
+    def test_model_name(self):
+        model = Cost231WIModel()
+        assert model.name == "COST-231-WI"
+
+    def test_distance_increases_loss(self):
+        model = Cost231WIModel()
+        loss_200 = model.calculate(make_input(distance_m=200)).path_loss_db
+        loss_1000 = model.calculate(make_input(distance_m=1000)).path_loss_db
+        assert loss_1000 > loss_200
+
+    def test_frequency_range(self):
+        model = Cost231WIModel()
+        assert model.is_valid_for(make_input(frequency_mhz=800))
+        assert model.is_valid_for(make_input(frequency_mhz=2000))
+        assert not model.is_valid_for(make_input(frequency_mhz=400))
+
+
+if __name__ == "__main__":
+    for cls_name, cls in [("COST231Hata", TestCost231Hata), ("COST231WI", TestCost231WI)]:
+        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 AssertionError as e:
+                print(f"  FAIL  {cls_name}.{method_name}: {e}")
+            except Exception as e:
+                print(f"  ERROR {cls_name}.{method_name}: {e}")
+    print("\nAll tests completed.")