refactor: unify container presence checks - find

diff --git a/src/bitcoin-cli.cpp b/src/bitcoin-cli.cpp
index 279aa89e..9efab160 100644
--- a/src/bitcoin-cli.cpp
+++ b/src/bitcoin-cli.cpp
@@ -1129,7 +1129,7 @@ static void ParseGetInfoResult(UniValue& result)
         const std::string proxy = network["proxy"].getValStr();
         if (proxy.empty()) continue;
         // Add proxy to ordered_proxy if has not been processed
-        if (proxy_networks.find(proxy) == proxy_networks.end()) ordered_proxies.push_back(proxy);
+        if (!proxy_networks.contains(proxy)) ordered_proxies.push_back(proxy);
 
         proxy_networks[proxy].push_back(network["name"].getValStr());
     }
diff --git a/src/common/args.cpp b/src/common/args.cpp
index 0b8d2e4d..f7d4652a 100644
--- a/src/common/args.cpp
+++ b/src/common/args.cpp
@@ -164,7 +164,7 @@ std::list<SectionInfo> ArgsManager::GetUnrecognizedSections() const
 
     LOCK(cs_args);
     std::list<SectionInfo> unrecognized = m_config_sections;
-    unrecognized.remove_if([](const SectionInfo& appeared){ return available_sections.find(appeared.m_name) != available_sections.end(); });
+    unrecognized.remove_if([](const SectionInfo& appeared){ return available_sections.contains(appeared.m_name); });
     return unrecognized;
 }
 
diff --git a/src/node/mini_miner.cpp b/src/node/mini_miner.cpp
index b70c7503..a2503c58 100644
--- a/src/node/mini_miner.cpp
+++ b/src/node/mini_miner.cpp
@@ -240,7 +240,7 @@ void MiniMiner::SanityCheck() const
                entry->second.GetModFeesWithAncestors() >= entry->second.GetModifiedFee();}));
     // None of the entries should be to-be-replaced transactions
     Assume(std::all_of(m_to_be_replaced.begin(), m_to_be_replaced.end(),
-        [&](const auto& txid){return m_entries_by_txid.find(txid) == m_entries_by_txid.end();}));
+        [&](const auto& txid){ return !m_entries_by_txid.contains(txid); }));
 }
 
 void MiniMiner::BuildMockTemplate(std::optional<CFeeRate> target_feerate)
diff --git a/src/node/utxo_snapshot.h b/src/node/utxo_snapshot.h
index e4eb6d60..3a493d44 100644
--- a/src/node/utxo_snapshot.h
+++ b/src/node/utxo_snapshot.h
@@ -77,7 +77,7 @@ public:
         // Read the version
         uint16_t version;
         s >> version;
-        if (m_supported_versions.find(version) == m_supported_versions.end()) {
+        if (!m_supported_versions.contains(version)) {
             throw std::ios_base::failure(strprintf("Version of snapshot %s does not match any of the supported versions.", version));
         }
 
diff --git a/src/policy/packages.cpp b/src/policy/packages.cpp
index 187bd467..0f04b4cf 100644
--- a/src/policy/packages.cpp
+++ b/src/policy/packages.cpp
@@ -26,7 +26,7 @@ bool IsTopoSortedPackage(const Package& txns, std::unordered_set<Txid, SaltedTxi
     // than its child.
     for (const auto& tx : txns) {
         for (const auto& input : tx->vin) {
-            if (later_txids.find(input.prevout.hash) != later_txids.end()) {
+            if (later_txids.contains(input.prevout.hash)) {
                 // The parent is a subsequent transaction in the package.
                 return false;
             }
@@ -62,7 +62,7 @@ bool IsConsistentPackage(const Package& txns)
             return false;
         }
         for (const auto& input : tx->vin) {
-            if (inputs_seen.find(input.prevout) != inputs_seen.end()) {
+            if (inputs_seen.contains(input.prevout)) {
                 // This input is also present in another tx in the package.
                 return false;
             }
diff --git a/src/rpc/util.cpp b/src/rpc/util.cpp
index 642b8c09..e9c97ba0 100644
--- a/src/rpc/util.cpp
+++ b/src/rpc/util.cpp
@@ -1172,7 +1172,7 @@ UniValue RPCResult::MatchesType(const UniValue& result) const
         std::map<std::string, UniValue> result_obj;
         result.getObjMap(result_obj);
         for (const auto& result_entry : result_obj) {
-            if (doc_keys.find(result_entry.first) == doc_keys.end()) {
+            if (!doc_keys.contains(result_entry.first)) {
                 errors.pushKV(result_entry.first, "key returned that was not in doc");
             }
         }
diff --git a/src/test/util_threadnames_tests.cpp b/src/test/util_threadnames_tests.cpp
index efa0b273..db3e90b7 100644
--- a/src/test/util_threadnames_tests.cpp
+++ b/src/test/util_threadnames_tests.cpp
@@ -58,7 +58,7 @@ BOOST_AUTO_TEST_CASE(util_threadnames_test_rename_threaded)
 
     // Names "test_thread.[n]" should exist for n = [0, 99]
     for (int i = 0; i < 100; ++i) {
-        BOOST_CHECK(names.find(TEST_THREAD_NAME_BASE + ToString(i)) != names.end());
+        BOOST_CHECK(names.contains(TEST_THREAD_NAME_BASE + ToString(i)));
     }
 
 }
diff --git a/src/txmempool.cpp b/src/txmempool.cpp
index e0d16a81..011de1d4 100644
--- a/src/txmempool.cpp
+++ b/src/txmempool.cpp
@@ -988,7 +988,7 @@ util::Result<std::pair<std::vector<FeeFrac>, std::vector<FeeFrac>>> CTxMemPool::
 CTxMemPool::ChangeSet::TxHandle CTxMemPool::ChangeSet::StageAddition(const CTransactionRef& tx, const CAmount fee, int64_t time, unsigned int entry_height, uint64_t entry_sequence, bool spends_coinbase, int64_t sigops_cost, LockPoints lp)
 {
     LOCK(m_pool->cs);
-    Assume(m_to_add.find(tx->GetHash()) == m_to_add.end());
+    Assume(!m_to_add.contains(tx->GetHash()));
     Assume(!m_dependencies_processed);
 
     // We need to process dependencies after adding a new transaction.
diff --git a/src/wallet/scriptpubkeyman.cpp b/src/wallet/scriptpubkeyman.cpp
index fc27da5d..aca9cca8 100644
--- a/src/wallet/scriptpubkeyman.cpp
+++ b/src/wallet/scriptpubkeyman.cpp
@@ -1107,8 +1107,8 @@ bool DescriptorScriptPubKeyMan::AddDescriptorKeyWithDB(WalletBatch& batch, const
     assert(!m_storage.IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS));
 
     // Check if provided key already exists
-    if (m_map_keys.find(pubkey.GetID()) != m_map_keys.end() ||
-        m_map_crypted_keys.find(pubkey.GetID()) != m_map_crypted_keys.end()) {
+    if (m_map_keys.contains(pubkey.GetID()) ||
+        m_map_crypted_keys.contains(pubkey.GetID())) {
         return true;
     }