refactor: Remove TEXT fields and use only reasoning_data for i18n

Completed the migration to structured reasoning_data for multilingual
dashboard support. Removed hardcoded TEXT fields (reasoning, consequence)
and updated all related code to use JSONB reasoning_data.

Changes:

1. Models Updated (removed TEXT fields):
   - PurchaseOrder: Removed reasoning, consequence TEXT columns
   - ProductionBatch: Removed reasoning TEXT column
   - Both now use only reasoning_data (JSONB/JSON)

2. Dashboard Service Updated:
   - Changed to return reasoning_data instead of TEXT fields
   - Creates default reasoning_data if missing
   - PO actions: reasoning_data with type and parameters
   - Production timeline: reasoning_data for each batch

3. Unified Schemas Updated (no separate migration):
   - services/procurement/migrations/001_unified_initial_schema.py
   - services/production/migrations/001_unified_initial_schema.py
   - Removed reasoning/consequence columns from table definitions
   - Updated comments to reflect i18n approach

Database Schema:
- purchase_orders: Only reasoning_data (JSONB)
- production_batches: Only reasoning_data (JSON)

Backend now generates:
{
  "type": "low_stock_detection",
  "parameters": {
    "supplier_name": "Harinas del Norte",
    "days_until_stockout": 3,
    ...
  },
  "consequence": {
    "type": "stockout_risk",
    "severity": "high"
  }
}

Next Steps:
- Frontend: Create i18n translation keys
- Frontend: Update components to translate reasoning_data
- Test multilingual support (ES, EN, CA)

services/production/app/models/production.py

@@ -133,16 +133,29 @@ class ProductionBatch(Base):
     delay_reason = Column(String(255), nullable=True)
     cancellation_reason = Column(String(255), nullable=True)
 
-    # JTBD Dashboard: Reasoning and context for user transparency
-    # Deferred loading to prevent breaking queries when columns don't exist yet
-    reasoning = deferred(Column(Text, nullable=True))  # Why this batch was scheduled (e.g., "Based on wedding order #1234")
-    reasoning_data = deferred(Column(JSON, nullable=True))  # Structured reasoning data
-    # reasoning_data structure: {
-    #   "trigger": "forecast" | "order" | "inventory" | "manual",
-    #   "forecast_id": "uuid",
-    #   "orders_fulfilled": [{"id": "uuid", "customer": "Maria's Bakery", "quantity": 100}],
-    #   "demand_score": 0-100,
-    #   "scheduling_priority_reason": "High demand + VIP customer"
+    # JTBD Dashboard: Structured reasoning data for i18n support
+    # Backend stores structured data, frontend translates using i18n
+    reasoning_data = Column(JSON, nullable=True)  # Structured reasoning data for multilingual support
+    # reasoning_data structure (see shared/schemas/reasoning_types.py):
+    # {
+    #   "type": "forecast_demand" | "customer_order" | "stock_replenishment" | etc.,
+    #   "parameters": {
+    #     "product_name": "Croissant",
+    #     "predicted_demand": 500,
+    #     "current_stock": 120,
+    #     "production_needed": 380,
+    #     "confidence_score": 87
+    #   },
+    #   "urgency": {
+    #     "level": "normal",
+    #     "ready_by_time": "08:00",
+    #     "customer_commitment": false
+    #   },
+    #   "metadata": {
+    #     "trigger_source": "orchestrator_auto",
+    #     "forecast_id": "uuid-here",
+    #     "ai_assisted": true
+    #   }
     # }
 
     # Timestamps
@@ -191,7 +204,6 @@ class ProductionBatch(Base):
             "quality_notes": self.quality_notes,
             "delay_reason": self.delay_reason,
             "cancellation_reason": self.cancellation_reason,
-            "reasoning": self.reasoning,
             "reasoning_data": self.reasoning_data,
             "created_at": self.created_at.isoformat() if self.created_at else None,
             "updated_at": self.updated_at.isoformat() if self.updated_at else None,