v3.42.11: Replace all Unicode emojis with ASCII text

- Replace all emoji characters with ASCII equivalents throughout codebase
- Replace Unicode box-drawing characters (═║╔╗╚╝━─) with ASCII (+|-=)
- Replace checkmarks (✓✗) with [OK]/[FAIL] markers
- 59 files updated, 741 lines changed
- Improves terminal compatibility and reduces visual noise

internal/backup/incremental_test.go

@@ -242,7 +242,7 @@ func TestIncrementalBackupRestore(t *testing.T) {
 		t.Errorf("Unchanged file base/12345/1235 not found in restore: %v", err)
 	}
 
-	t.Log("✅ Incremental backup and restore test completed successfully")
+	t.Log("[OK] Incremental backup and restore test completed successfully")
 }
 
 // TestIncrementalBackupErrors tests error handling