refactor: Use dedicated service client methods throughout dashboard

Completed migration from generic .get() calls to typed service client
methods for better code clarity and maintainability.

Changes:
- Production timeline: Use get_todays_batches() instead of .get()
- Insights: Use get_sustainability_widget() and get_stock_status()

All dashboard endpoints now use domain-specific typed methods instead
of raw HTTP paths, making the code more discoverable and type-safe.

services/orchestrator/app/api/dashboard.py

@@ -392,10 +392,7 @@ async def get_production_timeline(
         # Fetch today's production batches
         batches = []
         try:
-            batch_data = await production_client.get(
-                "/production/production-batches/today",
-                tenant_id=tenant_id
-            )
+            batch_data = await production_client.get_todays_batches(tenant_id)
             if batch_data:
                 batches = batch_data.get("batches", [])
         except Exception as e:
@@ -442,20 +439,14 @@ async def get_insights(
         # Sustainability data
         sustainability_data = {}
         try:
-            sustainability_data = await inventory_client.get(
-                "/inventory/sustainability/widget",
-                tenant_id=tenant_id
-            ) or {}
+            sustainability_data = await inventory_client.get_sustainability_widget(tenant_id) or {}
         except Exception as e:
             logger.warning(f"Failed to fetch sustainability data: {e}")
 
         # Inventory data
         inventory_data = {}
         try:
-            raw_inventory_data = await inventory_client.get(
-                "/inventory/dashboard/stock-status",
-                tenant_id=tenant_id
-            )
+            raw_inventory_data = await inventory_client.get_stock_status(tenant_id)
             # Handle case where API returns a list instead of dict
             if isinstance(raw_inventory_data, dict):
                 inventory_data = raw_inventory_data