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/app/main.py

@@ -6,7 +6,7 @@ from slowapi.util import get_remote_address
 
 from app.config import settings
 from app.middleware import verify_api_key
-from app.routers import avm, avm_industrial, avm_v2, moderation, nlp
+from app.routers import avm, avm_industrial, avm_v2, moderation, neighborhood, nlp
 
 limiter = Limiter(key_func=get_remote_address, default_limits=[settings.rate_limit])
 
@@ -35,6 +35,7 @@ app.include_router(avm.router)
 app.include_router(avm_v2.router)
 app.include_router(avm_industrial.router)
 app.include_router(moderation.router)
+app.include_router(neighborhood.router)
 app.include_router(nlp.router)