Crash fixes, reorg handling, and sync performance improvements

- Fix FFI panics with catch_unwind and safe CString construction
- Handle poisoned mutex/RwLock after prior panics instead of crashing
- Fix empty block list panics in clear_blocks and invalidate_block
- Reuse Tokio runtime across block fetch batches to reduce overhead
- Add fetch_blocks_with_runtime for caller-managed runtime lifecycle
- Update branding, dependencies, and checkpoints for DragonX

lib/build.rs

@@ -1,13 +1,13 @@
-// Copyright The Hush Developers  2019-2022
-// Released under the GPLv3
-fn main() -> Result<(), Box<dyn std::error::Error>> {
-    tonic_build::configure()
-         .build_server(false)
-         .compile(
-            &["proto/service.proto", "proto/compact_formats.proto"],
-            &["proto"],
-         )?;
-    println!("cargo:rerun-if-changed=proto/service.proto");
-    Ok(())
- }
- 
+// Copyright The Hush Developers  2019-2022
+// Released under the GPLv3
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    tonic_build::configure()
+         .build_server(false)
+         .compile(
+            &["proto/service.proto", "proto/compact_formats.proto"],
+            &["proto"],
+         )?;
+    println!("cargo:rerun-if-changed=proto/service.proto");
+    Ok(())
+ }
+