feat(ingestion): add first real-data importer flow

app/scouting/management/commands/import_hoopdata_demo_competition.py

@@ -0,0 +1,52 @@
+from __future__ import annotations
+
+import json
+from pathlib import Path
+
+from django.conf import settings
+from django.core.management.base import BaseCommand, CommandError
+
+from scouting.importers.hoopdata_demo import (
+    HoopDataDemoCompetitionImporter,
+    ImportValidationError,
+)
+
+
+class Command(BaseCommand):
+    help = "Import the first real-data MVP snapshot for the hoopdata_demo source (single competition scope)."
+
+    def add_arguments(self, parser):
+        parser.add_argument(
+            "--input",
+            default=str(
+                Path(settings.BASE_DIR)
+                / "scouting"
+                / "sample_data"
+                / "imports"
+                / "hoopdata_demo_serie_a2_2025_2026.json"
+            ),
+            help="Path to a hoopdata_demo competition snapshot JSON file.",
+        )
+
+    def handle(self, *args, **options):
+        input_path = Path(options["input"])
+        if not input_path.exists():
+            raise CommandError(f"Input file does not exist: {input_path}")
+
+        try:
+            payload = json.loads(input_path.read_text(encoding="utf-8"))
+            summary = HoopDataDemoCompetitionImporter(payload).run()
+        except json.JSONDecodeError as exc:
+            raise CommandError(f"Invalid JSON payload: {exc}") from exc
+        except ImportValidationError as exc:
+            raise CommandError(f"Import validation failed: {exc}") from exc
+
+        self.stdout.write(
+            self.style.SUCCESS(
+                "Imported hoopdata_demo competition snapshot successfully. "
+                f"Players +{summary.players_created}/~{summary.players_updated}, "
+                f"Teams +{summary.teams_created}/~{summary.teams_updated}, "
+                f"Contexts +{summary.contexts_created}/~{summary.contexts_updated}."
+            )
+        )
+        self.stdout.write(f"Source file: {input_path}")