Add enhanced configuration templates for adaptive I/O features

- Introduced a comprehensive configuration template (config-adaptive.toml) for adaptive I/O, enabling improved upload/download dual stack with various performance optimizations, security settings, and network resilience features.
- Created a test configuration template (test-config.toml) mirroring the adaptive configuration for testing purposes.
- Added a simple test configuration (test-simple-config.toml) for basic adaptive features testing with essential parameters.
- Included an empty Jupyter notebook (xep0363_analysis.ipynb) for future analysis related to XEP-0363.

cmd/server/upload_session.go

@@ -305,10 +305,6 @@ func (s *UploadSessionStore) cleanupExpiredSessions() {
 }
 
 // Helper functions
-func generateSessionID() string {
-	return fmt.Sprintf("%d_%s", time.Now().Unix(), randomString(16))
-}
-
 func getChunkSize() int64 {
 	// Default 5MB chunks, configurable
 	if conf.Uploads.ChunkSize != "" {