Add BLS client library, example scripts, and usage docs

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

bls_client/queries/productivity.py

@@ -0,0 +1,36 @@
+"""
+Pre-built productivity series IDs — Major Sector Productivity & Costs.
+"""
+
+from ..series import productivity
+
+def business_output_per_hour(seasonal: bool = True) -> str:
+    """Business sector output per hour worked (quarterly)."""
+    return productivity("business", "output_per_hour", seasonal)
+
+
+def business_unit_labor_cost(seasonal: bool = True) -> str:
+    """Business sector unit labor costs (quarterly)."""
+    return productivity("business", "unit_labor_cost", seasonal)
+
+
+def business_real_comp_per_hour(seasonal: bool = True) -> str:
+    """Business sector real compensation per hour."""
+    return productivity("business", "real_comp_per_hr", seasonal)
+
+
+def nonfarm_output_per_hour(seasonal: bool = True) -> str:
+    return productivity("nonfarm_business", "output_per_hour", seasonal)
+
+
+def manufacturing_output_per_hour(seasonal: bool = True) -> str:
+    return productivity("manufacturing", "output_per_hour", seasonal)
+
+
+def productivity_dashboard() -> dict:
+    return {
+        "Business Output/Hr":       business_output_per_hour(),
+        "Business Unit Labor Cost": business_unit_labor_cost(),
+        "Nonfarm Output/Hr":        nonfarm_output_per_hour(),
+        "Manufacturing Output/Hr":  manufacturing_output_per_hour(),
+    }