v3.42.33: Add cenkalti/backoff for exponential backoff retry

- Exponential backoff retry for all cloud operations (S3, Azure, GCS)
- RetryConfig presets: Default (5x), Aggressive (10x), Quick (3x)
- Smart error classification: IsPermanentError, IsRetryableError
- Automatic file position reset on upload retry
- Retry logging with wait duration
- Multipart uploads use aggressive retry (more tolerance)

bin/README.md

@@ -3,9 +3,9 @@
 This directory contains pre-compiled binaries for the DB Backup Tool across multiple platforms and architectures.
 
 ## Build Information
-- **Version**: 3.42.31
-- **Build Time**: 2026-01-14_15:07:12_UTC
-- **Git Commit**: dc6dfd8
+- **Version**: 3.42.32
+- **Build Time**: 2026-01-14_15:13:08_UTC
+- **Git Commit**: 6a24ee3
 
 ## Recent Updates (v1.1.0)
 - ✅ Fixed TUI progress display with line-by-line output