wallet: low-severity polish from the dev/v1.2.0 review

Follow-up nits surfaced by the multi-agent review of the dragonx..dev delta;
none are correctness/consensus bugs, all are defensive/consistency tidy-ups.
Builds clean; the diff was reviewed across concurrency, scheduler, and
tx-building lenses.

- wallet: default CWallet::fAutoShieldEnabled to false. init.cpp always
  recomputes it (ON only for CREATED/RESTORED seed provenance) before any
  ChainTip round, so this is behaviour-neutral in the normal path and stops a
  CWallet that skips that init from auto-enabling for provenance the gate would
  reject.

- wallet: clamp a loaded hdSeedOrigin to UNKNOWN when out of enum range, so a
  corrupt/hand-edited wallet.dat cannot claim a known-recoverable seed and flip
  autoshield ON.

- wallet: key the sweep and consolidation ops' NU-straddle guard, transaction
  builder height, and expiry off execution-time tipHeight instead of the stale
  enqueue-time targetHeight_ -- matching the autoshield op (65130c312) so the
  builder's consensus-branch selection agrees with the height the tx is signed
  for. (Sweep previously built at targetHeight_ but expired at the live tip.)

- wallet: on the sweep NU-straddle skip, set sweepComplete_ so the round backs
  nextSweep off one interval instead of re-dispatching a fresh sweep op every
  block through the activation window.

- init: clamp -autoshieldinterval below 5 up to the documented minimum of 5,
  rather than silently resetting it to the default 25.

- chainparams: make the ClearSeeds guard an exact "DRAGONX" match instead of a
  7-char prefix, so DRAGONX-prefixed assetchains (e.g. DRAGONX2) no longer
  inherit DragonX's seeds.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UtvyqQQSqR64DNEjUEuTmb

src/wallet/asyncrpcoperation_saplingconsolidation.cpp

@@ -107,8 +107,18 @@ bool AsyncRPCOperation_saplingconsolidation::main_impl() {
     auto opid=getId();
     LogPrintf("%s: Beginning AsyncRPCOperation_saplingconsolidation\n", opid);
     auto consensusParams = Params().GetConsensus();
-    auto nextActivationHeight = NextActivationHeight(targetHeight_, consensusParams);
-    if (nextActivationHeight && targetHeight_ + CONSOLIDATION_EXPIRY_DELTA >= nextActivationHeight.get()) {
+    int tipHeight;
+    {
+        LOCK(cs_main);
+        tipHeight = (chainActive.Tip() != NULL) ? chainActive.Tip()->GetHeight() : targetHeight_;
+    }
+
+    // Build and expire against tipHeight (execution-time), not the stale
+    // enqueue-time targetHeight_, so the builder's consensus-branch selection and
+    // the NU-straddle guard agree with the height the tx is signed for. Mirrors
+    // the autoshield op (commit 65130c312).
+    auto nextActivationHeight = NextActivationHeight(tipHeight, consensusParams);
+    if (nextActivationHeight && tipHeight + CONSOLIDATION_EXPIRY_DELTA >= nextActivationHeight.get()) {
         LogPrintf("%s: Consolidation txs would be created before a NU activation but may expire after. Skipping this round.\n",opid);
         setConsolidationResult(0, 0, std::vector<std::string>());
         return status;
@@ -189,8 +199,8 @@ bool AsyncRPCOperation_saplingconsolidation::main_impl() {
             if (fromNotes.size() < minQuantity)
               continue;
 
-            auto builder = TransactionBuilder(consensusParams, targetHeight_, pwalletMain);
-            builder.SetExpiryHeight(targetHeight_ + CONSOLIDATION_EXPIRY_DELTA);
+            auto builder = TransactionBuilder(consensusParams, tipHeight, pwalletMain);
+            builder.SetExpiryHeight(tipHeight + CONSOLIDATION_EXPIRY_DELTA);
             auto actualAmountToSend = amountToSend < fConsolidationTxFee ? 0 : amountToSend - fConsolidationTxFee;
             LogPrintf("%s: %s Beginning to create transaction with Sapling output amount=%s\n", __func__, opid, FormatMoney(actualAmountToSend));