feat(wasm-privacy-coin): thread owned flag into shardtree retention

Per-commitment ownership booleans are now threaded from the proto wire
format into the Rust shardtree append path. Owned leaves are assigned
Retention::Marked so the shardtree preserves their witness paths;
non-owned leaves remain Retention::Ephemeral (or Checkpoint for the
last commitment in a block).

Ticket: CSHLD-1208

Author: Ranjna-G

packages/wasm-privacy-coin/pom.xml

@@ -41,6 +41,12 @@
       <version>5.10.3</version>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>com.fasterxml.jackson.core</groupId>
+      <artifactId>jackson-databind</artifactId>
+      <version>2.17.0</version>
+      <scope>test</scope>
+    </dependency>
   </dependencies>
 
   <distributionManagement>

packages/wasm-privacy-coin/proto/privacy_coin.proto

@@ -15,6 +15,7 @@ message AppendCommitmentsRequest {
   uint32 block_height        = 1;
   repeated bytes commitments = 2;  // each exactly 32 bytes (cmx)
   optional bytes expected_root = 3; // 32 bytes; absent = skip verification
+  repeated bool owned        = 4;  // per-commitment ownership flag; absent/empty = all not-owned
 }
 
 message TruncateRequest {

packages/wasm-privacy-coin/src/lib.rs

@@ -186,8 +186,9 @@ pub unsafe extern "C" fn append_commitments(ptr: *const u8, len: u32) -> i32 {
                     Some(tree) => {
                         let commitments: Vec<Vec<u8>> =
                             req.commitments.iter().map(|b| b.to_vec()).collect();
+                        let owned = req.owned;
                         let exp = expected_root.as_deref();
-                        match tree.append_commitments(req.block_height, commitments, exp) {
+                        match tree.append_commitments(req.block_height, commitments, owned, exp) {
                             Ok(root) => write_ok_bytes(root),
                             Err(e) => {
                                 let (code, msg) = split_error(&e);

packages/wasm-privacy-coin/src/main/java/com/bitgo/wasm/privacycoin/zcash/ShieldedMerkleTree.java

@@ -100,12 +100,14 @@ public void ping() {
    *
    * @param blockHeight   block height (u32 range)
    * @param commitments   shielded note commitment values (cmx) for this block
+   * @param owned         per-commitment ownership flags; {@code null} or shorter list → remaining are false
    * @param expectedRoot  root to verify against; {@code null} to skip
    * @return computed root after appending
    * @throws WasmException with code {@code ROOT_MISMATCH} if verification fails
    */
   public ShieldedRoot appendCommitments(
-      long blockHeight, List<ShieldedCommitment> commitments, ShieldedRoot expectedRoot) {
+      long blockHeight, List<ShieldedCommitment> commitments, List<Boolean> owned,
+      ShieldedRoot expectedRoot) {
     requireU32(blockHeight, "blockHeight");
     Objects.requireNonNull(commitments, "commitments must not be null");
 
@@ -115,6 +117,9 @@ public ShieldedRoot appendCommitments(
         .addAllCommitments(commitments.stream()
             .map(c -> ByteString.copyFrom(c.bytes()))
             .toList());
+    if (owned != null && !owned.isEmpty()) {
+      req.addAllOwned(owned);
+    }
     if (expectedRoot != null) {
       req.setExpectedRoot(ByteString.copyFrom(expectedRoot.bytes()));
     }
@@ -123,11 +128,6 @@ public ShieldedRoot appendCommitments(
     return ShieldedRoot.of(unwrap(r, resp -> resp.getBytesValue().toByteArray()));
   }
 
-  /** Convenience overload — appends without root verification. */
-  public ShieldedRoot appendCommitments(long blockHeight, List<ShieldedCommitment> commitments) {
-    return appendCommitments(blockHeight, commitments, null);
-  }
-
   /**
    * Rolls the tree back to the checkpoint at the given block height.
    *