fix(agents): resolve import errors and complete Lampião IBGE integration

Fixed critical import errors preventing system initialization:
- ExternalAPIError → ExternalServiceError in dados_gov_api.py
- Created ToolResult dataclass in dados_gov_tool.py (removed non-existent base.py dependency)
- Added shutdown() method to LampiaoAgent to comply with BaseAgent abstract interface

Completed Lampião agent IBGE data integration:
- Initialized states_data attribute in __init__
- Added geographic_boundaries, regional_indicators, and spatial indices initialization
- Verified IBGE data loading: 27 states with population, GDP per capita, HDI, and density metrics
- All data sourced from IBGE 2023-2024 estimates

Testing:
- Created test_lampiao_ibge.py validation script
- Confirmed successful loading of all Brazilian state data
- Sample verification: São Paulo with 46.6M population, R$59.3k GDP/capita, 0.826 HDI

src/agents/lampiao.py

@@ -245,12 +245,20 @@ class LampiaoAgent(BaseAgent):
             "significance_level": 0.05
         }
         
-        # Brazilian regions data
-        self.brazil_regions = self._initialize_brazil_regions()
-        
+        # Brazilian states/regions data (IBGE)
+        self.states_data = self._initialize_brazil_regions()
+        self.brazil_regions = self.states_data  # Alias for compatibility
+
+        # Geographic data (initialized by initialize())
+        self.geographic_boundaries = {}
+        self.regional_indicators = {}
+        self.region_index = {}
+        self.capital_index = {}
+        self.state_name_index = {}
+
         # Spatial weights matrices cache
         self.spatial_weights = {}
-        
+
         # Analysis results cache
         self.analysis_cache = {}
     
@@ -900,4 +908,15 @@ class LampiaoAgent(BaseAgent):
 
         except Exception as e:
             self.logger.error(f"Failed to load IBGE indicators: {e}")
-            self.regional_indicators = {}
+            self.regional_indicators = {}
+
+    async def shutdown(self) -> None:
+        """Cleanup agent resources."""
+        self.logger.info("Lampião agent shutting down...")
+        # Clear cached data
+        self.geographic_boundaries = {}
+        self.regional_indicators = {}
+        self.region_index = {}
+        self.capital_index = {}
+        self.state_name_index = {}
+        self.logger.info("Lampião agent shutdown complete")

src/tools/dados_gov_api.py

@@ -14,12 +14,12 @@ import httpx
 from pydantic import BaseModel, Field
 
 from src.core.config import settings
-from src.core.exceptions import ExternalAPIError
+from src.core.exceptions import ExternalServiceError
 
 logger = logging.getLogger(__name__)
 
 
-class DadosGovAPIError(ExternalAPIError):
+class DadosGovAPIError(ExternalServiceError):
     """Custom exception for Dados.gov.br API errors"""
     pass
 

src/tools/dados_gov_tool.py

@@ -8,35 +8,42 @@ Open Data Portal (dados.gov.br) to enhance their investigations.
 import json
 import logging
 from typing import Any, Dict, List, Optional, Union
+from dataclasses import dataclass
 
 from src.services.dados_gov_service import DadosGovService
-from src.tools.base import BaseTool, ToolResult
 from src.tools.dados_gov_api import DadosGovAPIError
 
 logger = logging.getLogger(__name__)
 
 
-class DadosGovTool(BaseTool):
+@dataclass
+class ToolResult:
+    """Result from tool execution"""
+    success: bool
+    data: Any
+    error: Optional[str] = None
+
+
+class DadosGovTool:
     """
     Tool for accessing Brazilian Open Data Portal (dados.gov.br).
-    
+
     This tool enables agents to search for government datasets,
     analyze data availability, and find specific types of public data.
     """
-    
+
     name = "dados_gov_search"
     description = (
         "Search and analyze Brazilian government open data from dados.gov.br. "
         "Use this to find datasets about government spending, contracts, "
         "education, health, and other public data."
     )
-    
+
     def __init__(self):
         """Initialize the dados.gov.br tool"""
-        super().__init__()
         self.service = DadosGovService()
-        
-    async def _execute(
+
+    async def execute(
         self,
         query: Optional[str] = None,
         action: str = "search",