fix: add calendar property to date columns in model TML

Without calendar: calendar, ThoughtSpot treats date ATTRIBUTE columns
as plain text and rejects .weekly/.monthly time bucketing with
"Invalid value token: weekly".

Also: get_model_columns now returns type: DATE for calendar columns
so the liveboard creator correctly identifies date columns for
granularity-based queries.

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

thoughtspot_deployer.py

@@ -409,9 +409,11 @@ class ThoughtSpotDeployer:
                 # Map ThoughtSpot column types to SQL-like types for AI understanding
                 if col_type == 'MEASURE':
                     sql_type = 'NUMBER'  # Measures are numeric
+                elif col_props.get('calendar'):
+                    sql_type = 'DATE'    # Calendar attribute = date column
                 else:
-                    sql_type = 'VARCHAR'  # Attributes are typically strings
-                
+                    sql_type = 'VARCHAR'  # Other attributes are typically strings
+
                 columns.append({
                     'name': col_name,
                     'type': sql_type,
@@ -837,11 +839,16 @@ class ThoughtSpotDeployer:
                 # Add aggregation for measures
                 if aggregation:
                     column_def['properties']['aggregation'] = aggregation
-                
+
+                # Add calendar property for DATE columns so ThoughtSpot enables
+                # time bucketing (.weekly, .monthly, etc.) on them
+                if self._map_data_type(col['type']) == 'DATE':
+                    column_def['properties']['calendar'] = 'calendar'
+
                 model['model']['columns'].append(column_def)
-        
+
         # Generate YAML output with proper formatting
-        yaml_output = yaml.dump(model, default_flow_style=False, sort_keys=False, 
+        yaml_output = yaml.dump(model, default_flow_style=False, sort_keys=False,
                                default_style=None, indent=2, width=120)
         
         # Validate the generated YAML
@@ -1015,16 +1022,21 @@ class ThoughtSpotDeployer:
                         'index_type': 'DONT_INDEX'
                     }
                 }
-                
+
                 if aggregation:
                     column_def['properties']['aggregation'] = aggregation
-                
+
+                # Add calendar property for DATE columns so ThoughtSpot enables
+                # time bucketing (.weekly, .monthly, etc.) on them
+                if self._map_data_type(col['type']) == 'DATE':
+                    column_def['properties']['calendar'] = 'calendar'
+
                 model['model']['columns'].append(column_def)
-        
+
         # Generate YAML output with validation
-        yaml_output = yaml.dump(model, default_flow_style=False, sort_keys=False, 
+        yaml_output = yaml.dump(model, default_flow_style=False, sort_keys=False,
                                default_style=None, indent=2, width=120)
-        
+
         # Fix YAML reserved word quoting - 'on' gets quoted because it's a YAML boolean
         # ThoughtSpot needs it unquoted
         yaml_output = yaml_output.replace("'on':", "on:")