feat(analytics): add Python NeighborhoodScore service + NestJS HTTP proxy (TEC-2756)

- libs/ai-services: new POST /neighborhood/score router computing weighted
  6-axis livability score from per-category POI counts; algorithm versioned
  for future iteration (sigmoid curves, percentile thresholds).
- apps/api: HttpNeighborhoodScoreService proxies to Python first, falls back
  to PrismaNeighborhoodScoreService when AI service unavailable. Mirrors the
  HttpAVMService pattern. Existing GET /analytics/neighborhoods/:district/score
  endpoint and CQRS handler now flow through the proxy.
- AnalyticsModule binds Http variant by default, retains Prisma variant as
  injectable fallback.
- Tests: 5 pytest cases for Python heuristic, 4 vitest cases for HTTP proxy
  fallback behaviour.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

libs/ai-services/tests/test_neighborhood.py

@@ -0,0 +1,119 @@
+from fastapi.testclient import TestClient
+
+from app.main import app
+
+client = TestClient(app)
+
+
+def test_zero_counts_yields_zero_score():
+    resp = client.post(
+        "/neighborhood/score",
+        json={
+            "district": "Quận 7",
+            "city": "Hồ Chí Minh",
+            "poi_counts": {
+                "education": 0,
+                "healthcare": 0,
+                "transport": 0,
+                "shopping": 0,
+                "greenery": 0,
+                "safety": 0,
+            },
+        },
+    )
+    assert resp.status_code == 200
+    data = resp.json()
+    assert data["total_score"] == 0
+    assert data["education_score"] == 0
+    assert data["algorithm_version"].startswith("neighborhood-heuristic")
+
+
+def test_saturated_counts_yields_one_hundred():
+    resp = client.post(
+        "/neighborhood/score",
+        json={
+            "district": "Quận 1",
+            "city": "Hồ Chí Minh",
+            "poi_counts": {
+                "education": 50,
+                "healthcare": 50,
+                "transport": 50,
+                "shopping": 50,
+                "greenery": 50,
+                "safety": 50,
+            },
+        },
+    )
+    assert resp.status_code == 200
+    data = resp.json()
+    assert data["total_score"] == 100.0
+    assert data["education_score"] == 10
+    assert data["safety_score"] == 10
+
+
+def test_partial_counts_apply_weighted_average():
+    # Hit the linear cap on transport+greenery only; others 0.
+    # transport weight 20 + greenery 15 = 35 → expect total 35.0.
+    resp = client.post(
+        "/neighborhood/score",
+        json={
+            "district": "Bình Thạnh",
+            "city": "Hồ Chí Minh",
+            "poi_counts": {
+                "education": 0,
+                "healthcare": 0,
+                "transport": 12,
+                "shopping": 0,
+                "greenery": 6,
+                "safety": 0,
+            },
+        },
+    )
+    assert resp.status_code == 200
+    data = resp.json()
+    assert data["transport_score"] == 10
+    assert data["greenery_score"] == 10
+    assert data["total_score"] == 35.0
+    assert data["poi_counts"]["transport"] == 12
+
+
+def test_below_max_uses_linear_scale():
+    # education max=15, count=3 → 2.0; weight 20 → contributes 4.0
+    resp = client.post(
+        "/neighborhood/score",
+        json={
+            "district": "Quận 3",
+            "city": "Hồ Chí Minh",
+            "poi_counts": {
+                "education": 3,
+                "healthcare": 0,
+                "transport": 0,
+                "shopping": 0,
+                "greenery": 0,
+                "safety": 0,
+            },
+        },
+    )
+    assert resp.status_code == 200
+    data = resp.json()
+    assert data["education_score"] == 2.0
+    assert data["total_score"] == 4.0
+
+
+def test_validation_rejects_negative_count():
+    resp = client.post(
+        "/neighborhood/score",
+        json={
+            "district": "Quận 1",
+            "city": "Hồ Chí Minh",
+            "poi_counts": {
+                "education": -1,
+                "healthcare": 0,
+                "transport": 0,
+                "shopping": 0,
+                "greenery": 0,
+                "safety": 0,
+            },
+        },
+    )
+    assert resp.status_code == 422