fix(storage): detect signet_<hash> directories and respect network arg

.github/workflows/ci.yml

@@ -392,6 +392,12 @@ jobs:
       - name: Run tests (stratum-v2 feature, lib)
         run: cargo test --features stratum-v2 --lib
 
+      # `rocksdb` is not in default features but gates Bitcoin Core import / block-file
+      # reuse (src/storage/bitcoin_core_*, core_reuse_tests, tests/bitcoin_core_tests.rs,
+      # tests/core_drop_in_integration.rs). Without this step that code is never tested.
+      - name: Run tests (rocksdb feature)
+        run: cargo test --features rocksdb
+
       - name: Dump disk usage on failure
         if: failure()
         run: |

src/storage/bitcoin_core_blocks.rs

@@ -183,6 +183,11 @@ impl BitcoinCoreBlockReader {
         })
     }
 
+    /// Network whose block magic this reader expects.
+    pub fn network(&self) -> CoreDataNetwork {
+        self.network
+    }
+
     /// Get the magic bytes for the network
     fn get_magic(&self) -> &[u8; 4] {
         network_magic(self.network)