feat: add operational Dashboard

backend/app/locations/repository.py

@@ -201,3 +201,31 @@ class LocationMapRepository:
             "positions": positions,
             "virtual_miners": virtual_miners,
         }
+
+    def summarize_locations(self, *, include_miner_counts: bool) -> dict[str, Any]:
+        miner_counts = (
+            "count(DISTINCT lp.miner_id)::integer AS mapped_miners, "
+            "(SELECT count(*)::integer FROM miners WHERE NOT EXISTS ("
+            "SELECT 1 FROM location_positions assigned "
+            "WHERE assigned.miner_id = miners.id)) AS unmapped_miners"
+            if include_miner_counts
+            else "NULL::integer AS mapped_miners, NULL::integer AS unmapped_miners"
+        )
+        with self._connection_scope() as connection:
+            with connection.cursor(row_factory=dict_row) as cur:
+                cur.execute(
+                    f"""
+                    SELECT (SELECT count(*)::integer FROM sites) AS sites,
+                        (SELECT count(*)::integer FROM rooms) AS rooms,
+                        count(lp.id)::integer AS positions,
+                        count(lp.id) FILTER (
+                            WHERE lp.miner_id IS NOT NULL
+                        )::integer AS occupied_positions,
+                        count(lp.id) FILTER (
+                            WHERE lp.miner_id IS NULL
+                        )::integer AS empty_positions,
+                        {miner_counts}
+                    FROM location_positions AS lp
+                    """
+                )
+                return dict(cur.fetchone())