feat: add SQLCipher database encryption support and consolidate agent documentation

- Add SQLCipher encryption for ait-mainnet database with configurable flag
- Add db_encryption_enabled and db_encryption_key_path config settings
- Implement encryption key loading and PRAGMA key setup via connection events
- Add shutdown_db function for proper database cleanup
- Export middleware classes in aitbc/__init__.py
- Fix import path in sync.py for settings
- Remove duplicate agent documentation from docs

packages/py/aitbc-core/src/aitbc/__init__.py

@@ -11,6 +11,24 @@ from .middleware import (
     ErrorHandlerMiddleware,
 )
 
+# Re-export constants for compatibility
+from .constants import (
+    DATA_DIR,
+    LOG_DIR,
+    CONFIG_DIR,
+    REPO_DIR,
+    KEYSTORE_DIR,
+    BLOCKCHAIN_DATA_DIR,
+    MARKETPLACE_DATA_DIR,
+    ENV_FILE,
+    NODE_ENV_FILE,
+    BLOCKCHAIN_RPC_PORT,
+    BLOCKCHAIN_P2P_PORT,
+    AGENT_COORDINATOR_PORT,
+    MARKETPLACE_PORT,
+    PACKAGE_VERSION,
+)
+
 __all__ = [
     "logging",
     "configure_logging",
@@ -19,4 +37,18 @@ __all__ = [
     "PerformanceLoggingMiddleware",
     "RequestValidationMiddleware",
     "ErrorHandlerMiddleware",
+    "DATA_DIR",
+    "LOG_DIR",
+    "CONFIG_DIR",
+    "REPO_DIR",
+    "KEYSTORE_DIR",
+    "BLOCKCHAIN_DATA_DIR",
+    "MARKETPLACE_DATA_DIR",
+    "ENV_FILE",
+    "NODE_ENV_FILE",
+    "BLOCKCHAIN_RPC_PORT",
+    "BLOCKCHAIN_P2P_PORT",
+    "AGENT_COORDINATOR_PORT",
+    "MARKETPLACE_PORT",
+    "PACKAGE_VERSION",
 ]

packages/py/aitbc-core/src/aitbc/constants.py

@@ -0,0 +1,30 @@
+"""
+AITBC Common Constants
+Centralized constants for AITBC system paths and configuration
+"""
+
+from pathlib import Path
+
+# AITBC System Paths
+DATA_DIR = Path("/var/lib/aitbc")
+CONFIG_DIR = Path("/etc/aitbc")
+LOG_DIR = Path("/var/log/aitbc")
+REPO_DIR = Path("/opt/aitbc")
+
+# Common subdirectories
+KEYSTORE_DIR = DATA_DIR / "keystore"
+BLOCKCHAIN_DATA_DIR = DATA_DIR / "data" / "ait-mainnet"
+MARKETPLACE_DATA_DIR = DATA_DIR / "data" / "marketplace"
+
+# Configuration files
+ENV_FILE = CONFIG_DIR / ".env"
+NODE_ENV_FILE = CONFIG_DIR / "node.env"
+
+# Default ports
+BLOCKCHAIN_RPC_PORT = 8006
+BLOCKCHAIN_P2P_PORT = 7070
+AGENT_COORDINATOR_PORT = 9001
+MARKETPLACE_PORT = 8081
+
+# Package version
+PACKAGE_VERSION = "0.3.0"