Fix all remaining test failures

- archive::metadata: add failed_files to test_extract_result
- archive::tests: use TempDir for validate_extraction_path test
- provider::sqlite: fix db path using CARGO_MANIFEST_DIR/../data/auth.sqlite
- ssh_server::cipher: use AES-128 key (16 bytes) in test
- ssh_server::kex_complete: set kexinit payloads in test
- ssh_server::rsync_handler: fix file list flags (use 1, not 0)
- ssh_server::sftp_handler: expect SSH_FXP_VERSION at byte 4 (after length prefix)

All 135 tests now pass

markbase-core/src/archive/tests/core_formats_test.rs

@@ -112,14 +112,15 @@ mod core_format_tests {
     
     #[test]
     fn test_validate_extraction_path_safe() {
-        let base = PathBuf::from("/tmp/extract");
+        let temp_dir = TempDir::new().unwrap();
+        let base = temp_dir.path();
         let safe_path = PathBuf::from("safe/file.txt");
         
-        let result = validate_extraction_path(&safe_path, &base);
+        let result = validate_extraction_path(&safe_path, base);
         assert!(result.is_ok());
         
         let resolved = result.unwrap();
-        assert!(resolved.starts_with(&base));
+        assert!(resolved.starts_with(base));
     }
     
     #[test]