v3.42.9: Fix all timeout bugs and deadlocks

CRITICAL FIXES:
- Encryption detection false positive (IsBackupEncrypted returned true for ALL files)
- 12 cmd.Wait() deadlocks fixed with channel-based context handling
- TUI timeout bugs: 60s->10min for safety checks, 15s->60s for DB listing
- diagnose.go timeouts: 60s->5min for tar/pg_restore operations
- Panic recovery added to parallel backup/restore goroutines
- Variable shadowing fix in restore/engine.go

These bugs caused pg_dump backups to fail through TUI for months.

bin/README.md

@@ -4,8 +4,8 @@ This directory contains pre-compiled binaries for the DB Backup Tool across mult
 
 ## Build Information
 - **Version**: 3.42.1
-- **Build Time**: 2026-01-07_19:40:21_UTC
-- **Git Commit**: 3653ced
+- **Build Time**: 2026-01-08_04:54:46_UTC
+- **Git Commit**: 627061c
 
 ## Recent Updates (v1.1.0)
 - ✅ Fixed TUI progress display with line-by-line output