chore(security,refactor): extract sanitization and improve code quality (#41)

* chore(security,refactor): extract sanitization and improve code quality

- [x] Extract sanitization functions to dedicated sanitization.go module
- [x] Add comprehensive golangci-lint v2 configuration with security rules
- [x] Replace interface{} with any type throughout codebase
- [x] Add admin API authentication security warning
- [x] Extract WebSocket and stats streaming constants
- [x] Add best-effort error handling comments for resource cleanup
- [x] Expand sensitive field patterns for improved PII redaction
- [x] Simplify safety checks and remove redundant nil validations
- [x] Improve test coverage for password field redaction patterns

* refactor: replace interface{} with any type alias

- [x] Replace all `map[string]interface{}` with `map[string]any`
- [x] Replace all `interface{}` with `any` in function signatures and type definitions
- [x] Update sync.Pool New function returns from `interface{}` to `any`
- [x] Add package documentation comments to 8 package files
- [x] Update type assertions and casts to work with `any` type

connection_pool.go

@@ -118,7 +118,7 @@ func (cpm *ConnectionPoolManager) cleanIdleConnections() {
 		if cpm.logger != nil {
 			cpm.logger.Debug(&libpack_logging.LogMessage{
 				Message: "Cleaned idle HTTP connections",
-				Pairs: map[string]interface{}{
+				Pairs: map[string]any{
 					"active_connections": cpm.activeConnections.Load(),
 					"total_connections":  cpm.totalConnections.Load(),
 				},
@@ -172,7 +172,7 @@ func (cpm *ConnectionPoolManager) performKeepAlive() {
 		if cpm.logger != nil {
 			cpm.logger.Debug(&libpack_logging.LogMessage{
 				Message: "Keep-alive request failed",
-				Pairs: map[string]interface{}{
+				Pairs: map[string]any{
 					"error": err.Error(),
 				},
 			})
@@ -202,7 +202,7 @@ func (cpm *ConnectionPoolManager) checkAndRecover() {
 		if cpm.logger != nil {
 			cpm.logger.Warning(&libpack_logging.LogMessage{
 				Message: "Connection pool health degraded, attempting recovery",
-				Pairs: map[string]interface{}{
+				Pairs: map[string]any{
 					"consecutive_failures": failures,
 				},
 			})
@@ -246,8 +246,8 @@ func (cpm *ConnectionPoolManager) RecordConnectionFailure() {
 }
 
 // GetConnectionStats returns current connection statistics
-func (cpm *ConnectionPoolManager) GetConnectionStats() map[string]interface{} {
-	return map[string]interface{}{
+func (cpm *ConnectionPoolManager) GetConnectionStats() map[string]any {
+	return map[string]any{
 		"active_connections":    cpm.activeConnections.Load(),
 		"total_connections":     cpm.totalConnections.Load(),
 		"connection_failures":   cpm.connectionFailures.Load(),
@@ -296,7 +296,7 @@ func InitializeConnectionPool(client *fasthttp.Client) {
 	connectionPoolMutex.Lock()
 	defer connectionPoolMutex.Unlock()
 	if connectionPoolManager != nil {
-		connectionPoolManager.Shutdown()
+		_ = connectionPoolManager.Shutdown() // Best-effort cleanup
 	}
 	connectionPoolManager = NewConnectionPoolManager(client)
 }
@@ -306,7 +306,7 @@ func ShutdownConnectionPool() {
 	connectionPoolMutex.Lock()
 	defer connectionPoolMutex.Unlock()
 	if connectionPoolManager != nil {
-		connectionPoolManager.Shutdown()
+		_ = connectionPoolManager.Shutdown() // Best-effort cleanup
 		connectionPoolManager = nil
 	}
 }