feat: fix missing modules and dependencies for test compatibility

CODEBASE FIXES: Resolve real import and dependency issues

Fixed Issues:
1. Missing aitbc.logging module - created aitbc/ package with logging.py
2. Missing src.message_protocol - created agent-protocols/src/message_protocol.py
3. Missing src.task_manager - created agent-protocols/src/task_manager.py
4. SQLAlchemy metadata conflicts - added extend_existing=True to Block model
5. Missing dependencies - added slowapi>=0.1.0 and pynacl>=1.5.0

New Modules Created:
- aitbc/__init__.py - AITBC package initialization
- aitbc/logging.py - Centralized logging utilities with get_logger()
- apps/agent-protocols/src/__init__.py - Agent protocols package
- apps/agent-protocols/src/message_protocol.py - MessageProtocol, MessageTypes, AgentMessageClient
- apps/agent-protocols/src/task_manager.py - TaskManager, TaskStatus, TaskPriority, Task

Database Fixes:
- apps/blockchain-node/src/aitbc_chain/models.py - Added extend_existing=True to resolve metadata conflicts

Dependencies Added:
- slowapi>=0.1.0 - For slowapi.errors import
- pynacl>=1.5.0 - For nacl.signing import

Expected Results:
- aitbc.logging imports should work
- src.message_protocol imports should work
- src.task_manager imports should work
- SQLAlchemy metadata conflicts resolved
- Missing dependency imports resolved
- More tests should collect and run successfully

This addresses the root cause issues in the codebase rather than
working around them with test filtering.

apps/agent-protocols/src/task_manager.py

@@ -0,0 +1,128 @@
+"""
+Task Manager for AITBC Agents
+Handles task creation, assignment, and tracking
+"""
+
+import uuid
+from datetime import datetime, timedelta
+from typing import Dict, Any, Optional, List
+from enum import Enum
+
+class TaskStatus(Enum):
+    """Task status enumeration"""
+    PENDING = "pending"
+    IN_PROGRESS = "in_progress"
+    COMPLETED = "completed"
+    FAILED = "failed"
+    CANCELLED = "cancelled"
+
+class TaskPriority(Enum):
+    """Task priority enumeration"""
+    LOW = "low"
+    MEDIUM = "medium"
+    HIGH = "high"
+    URGENT = "urgent"
+
+class Task:
+    """Task representation"""
+    
+    def __init__(
+        self,
+        task_id: str,
+        title: str,
+        description: str,
+        assigned_to: str,
+        priority: TaskPriority = TaskPriority.MEDIUM,
+        created_by: Optional[str] = None
+    ):
+        self.task_id = task_id
+        self.title = title
+        self.description = description
+        self.assigned_to = assigned_to
+        self.priority = priority
+        self.created_by = created_by or assigned_to
+        self.status = TaskStatus.PENDING
+        self.created_at = datetime.utcnow()
+        self.updated_at = datetime.utcnow()
+        self.completed_at = None
+        self.result = None
+        self.error = None
+
+class TaskManager:
+    """Task manager for agent coordination"""
+    
+    def __init__(self):
+        self.tasks = {}
+        self.task_history = []
+    
+    def create_task(
+        self,
+        title: str,
+        description: str,
+        assigned_to: str,
+        priority: TaskPriority = TaskPriority.MEDIUM,
+        created_by: Optional[str] = None
+    ) -> Task:
+        """Create a new task"""
+        task_id = str(uuid.uuid4())
+        task = Task(
+            task_id=task_id,
+            title=title,
+            description=description,
+            assigned_to=assigned_to,
+            priority=priority,
+            created_by=created_by
+        )
+        
+        self.tasks[task_id] = task
+        return task
+    
+    def get_task(self, task_id: str) -> Optional[Task]:
+        """Get a task by ID"""
+        return self.tasks.get(task_id)
+    
+    def update_task_status(
+        self,
+        task_id: str,
+        status: TaskStatus,
+        result: Optional[Dict[str, Any]] = None,
+        error: Optional[str] = None
+    ) -> bool:
+        """Update task status"""
+        task = self.get_task(task_id)
+        if not task:
+            return False
+        
+        task.status = status
+        task.updated_at = datetime.utcnow()
+        
+        if status == TaskStatus.COMPLETED:
+            task.completed_at = datetime.utcnow()
+            task.result = result
+        elif status == TaskStatus.FAILED:
+            task.error = error
+        
+        return True
+    
+    def get_tasks_by_agent(self, agent_id: str) -> List[Task]:
+        """Get all tasks assigned to an agent"""
+        return [
+            task for task in self.tasks.values()
+            if task.assigned_to == agent_id
+        ]
+    
+    def get_tasks_by_status(self, status: TaskStatus) -> List[Task]:
+        """Get all tasks with a specific status"""
+        return [
+            task for task in self.tasks.values()
+            if task.status == status
+        ]
+    
+    def get_overdue_tasks(self, hours: int = 24) -> List[Task]:
+        """Get tasks that are overdue"""
+        cutoff_time = datetime.utcnow() - timedelta(hours=hours)
+        return [
+            task for task in self.tasks.values()
+            if task.status in [TaskStatus.PENDING, TaskStatus.IN_PROGRESS] and
+            task.created_at < cutoff_time
+        ]