wallet: add z_autoshieldstatus

Auto-shielding could silently decline to run with no way to ask why. The
destination it resolves was equally invisible: the only evidence was a LogPrintf
emitted once per round, so an operator wanting to know where their mined coinbase
was going had to grep debug.log.

z_autoshieldstatus reports the enable state, whether a round is in flight, the
next height, interval, fee, minimum utxos, and the resolved destination -- plus
the HD seed provenance in both numeric and readable form, whether the seed is
phrase-recoverable, and a disabled_reason explaining why it is off when it is.

That last field is the point. "autoshield": false on its own does not distinguish
an operator who passed -autoshield=0 from a wallet whose seed provenance is not
known-recoverable, and those need different responses.

Mirrors z_sweepstatus in shape and registration.

Verified on all three branches:
  fresh wallet    -> autoshield true, origin 1 "created on an empty wallet",
                     seed_recoverable true, disabled_reason ""
  -autoshield=0   -> disabled_reason "disabled by -autoshield=0"
  upgraded wallet -> autoshield false, origin 4 "predates provenance recording",
                     seed_recoverable false, disabled_reason "HD seed origin is
                     not known-recoverable; back the seed up and pass -autoshield=1"

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

src/rpc/server.h

@@ -369,6 +369,7 @@ extern UniValue z_gettotalbalance(const UniValue& params, bool fHelp, const CPub
 extern UniValue z_mergetoaddress(const UniValue& params, bool fHelp, const CPubKey& mypk); // in rpcwallet.cpp
 extern UniValue z_sendmany(const UniValue& params, bool fHelp, const CPubKey& mypk); // in rpcwallet.cpp
 extern UniValue z_sweepstatus(const UniValue& params, bool fHelp, const CPubKey& mypk); // in rpcwallet.cpp
+extern UniValue z_autoshieldstatus(const UniValue& params, bool fHelp, const CPubKey& mypk); // in rpcwallet.cpp
 extern UniValue z_consolidationstatus(const UniValue& params, bool fHelp, const CPubKey& mypk); // in rpcwallet.cpp
 extern UniValue z_shieldcoinbase(const UniValue& params, bool fHelp, const CPubKey& mypk); // in rpcwallet.cpp
 extern UniValue z_getoperationstatus(const UniValue& params, bool fHelp, const CPubKey& mypk); // in rpcwallet.cpp

src/wallet/rpcwallet.cpp

@@ -3345,6 +3345,77 @@ UniValue z_sweepstatus(const UniValue& params, bool fHelp, const CPubKey& mypk)
       return ret;
 }
 
+UniValue z_autoshieldstatus(const UniValue& params, bool fHelp, const CPubKey& mypk)
+{
+    if (!EnsureWalletIsAvailable(fHelp))
+        return NullUniValue;
+
+    if (fHelp || params.size() > 0)
+        throw runtime_error(
+            "z_autoshieldstatus\n"
+            "\nReport the state of automatic coinbase shielding: whether it is on, where it sends,\n"
+            "and -- when it is off -- why.\n"
+            "\nResult:\n"
+            "{\n"
+            "  \"autoshield\" : true|false,          (boolean) whether auto-shielding is enabled\n"
+            "  \"running\" : true|false,             (boolean) whether a round is in flight\n"
+            "  \"next_autoshield\" : n,              (numeric) height of the next round\n"
+            "  \"autoshieldinterval\" : n,           (numeric) blocks between rounds\n"
+            "  \"autoshieldaddress\" : \"zaddr\",     (string) resolved destination; empty until first resolved\n"
+            "  \"autoshieldfee\" : n,                (numeric) fee in puposhis\n"
+            "  \"autoshieldminutxos\" : n,           (numeric) minimum matured coinbase utxos per round\n"
+            "  \"hdseedorigin\" : n,                 (numeric) 0 unrecorded, 1 created, 2 restored, 3 retrofit, 4 unknown\n"
+            "  \"hdseedorigin_desc\" : \"...\",       (string) readable form of hdseedorigin\n"
+            "  \"seed_recoverable\" : true|false,    (boolean) whether a seed phrase can be exported\n"
+            "  \"disabled_reason\" : \"...\"          (string) why auto-shielding is not running, if it is not\n"
+            "}\n"
+            "\nExamples:\n"
+            + HelpExampleCli("z_autoshieldstatus", "")
+            + HelpExampleRpc("z_autoshieldstatus", "")
+        );
+
+    LOCK2(cs_main, pwalletMain->cs_wallet);
+
+    UniValue ret(UniValue::VOBJ);
+    ret.push_back(Pair("autoshield", pwalletMain->fAutoShieldEnabled));
+    ret.push_back(Pair("running", pwalletMain->fAutoShieldRunning));
+    ret.push_back(Pair("next_autoshield", pwalletMain->nextAutoShield));
+    ret.push_back(Pair("autoshieldinterval", pwalletMain->autoShieldInterval));
+    ret.push_back(Pair("autoshieldaddress", pwalletMain->autoShieldAddress));
+    ret.push_back(Pair("autoshieldfee", pwalletMain->autoShieldFee));
+    ret.push_back(Pair("autoshieldminutxos", pwalletMain->autoShieldMinUtxos));
+
+    int origin = pwalletMain->hdSeedOrigin;
+    std::string desc;
+    switch (origin) {
+        case CWallet::HDSEED_ORIGIN_CREATED:  desc = "created on an empty wallet"; break;
+        case CWallet::HDSEED_ORIGIN_RESTORED: desc = "restored from -mnemonic/-hdseed"; break;
+        case CWallet::HDSEED_ORIGIN_RETROFIT: desc = "retrofitted onto a pre-existing wallet"; break;
+        case CWallet::HDSEED_ORIGIN_UNKNOWN:  desc = "predates provenance recording"; break;
+        default:                              desc = "not yet recorded"; break;
+    }
+    ret.push_back(Pair("hdseedorigin", origin));
+    ret.push_back(Pair("hdseedorigin_desc", desc));
+    ret.push_back(Pair("seed_recoverable", pwalletMain->IsMnemonicSeed()));
+
+    // Say why it is off. A silent "false" is exactly what made the destination
+    // un-inspectable in the first place.
+    std::string why = "";
+    if (!pwalletMain->fAutoShieldEnabled) {
+        if (origin != CWallet::HDSEED_ORIGIN_CREATED && origin != CWallet::HDSEED_ORIGIN_RESTORED)
+            why = "HD seed origin is not known-recoverable; back the seed up and pass -autoshield=1";
+        else
+            why = "disabled by -autoshield=0";
+    } else if (pwalletMain->IsLocked()) {
+        why = "wallet is locked; rounds are skipped until it is unlocked";
+    } else if (pwalletMain->autoShieldAddress.empty()) {
+        why = "";
+    }
+    ret.push_back(Pair("disabled_reason", why));
+
+    return ret;
+}
+
 UniValue z_listreceivedaddress(const UniValue& params, bool fHelp,const CPubKey&)
 {
   if (!EnsureWalletIsAvailable(fHelp))
@@ -6349,6 +6420,7 @@ static const CRPCCommand commands[] =
     { "wallet",             "z_gettotalbalance",        &z_gettotalbalance,        false },
     { "wallet",             "z_mergetoaddress",         &z_mergetoaddress,         false },
     { "wallet",             "z_sweepstatus",            &z_sweepstatus,            true  },
+    { "wallet",             "z_autoshieldstatus",       &z_autoshieldstatus,       true  },
     { "wallet",             "z_consolidationstatus",    &z_consolidationstatus,    true  },
     { "wallet",             "z_sendmany",               &z_sendmany,               false },
     { "wallet",             "z_shieldcoinbase",         &z_shieldcoinbase,         false },