feat(wallet): persist history and surface pending sends

Add an encrypted SQLite transaction history cache with cached tip metadata and
per-address shielded scan progress so startup and full refreshes avoid
re-scanning every z-address while still invalidating on wallet/address/rescan
changes.

Improve wallet history loading by paging transparent transactions, preserving
cached shielded and sent rows, keeping recent/unconfirmed activity visible, and
classifying mining-address receives. Show z_sendmany opid sends immediately in
History and Overview, pin pending rows through refreshes, and apply optimistic
address/balance debits until opids resolve.

Add timestamped RPC console tracing by source/method without logging params or
results, reduce redundant refresh/RPC calls, and cache Explorer recent block
summaries in SQLite.

Expand focused tests for transaction cache encryption, scan-progress
persistence/invalidation, history preservation, operation-status parsing,
pending send visibility, and Explorer/RPC refresh behavior.

src/config/settings.h

@@ -147,6 +147,7 @@ public:
         std::string label;
         std::string icon;       // material icon name, e.g. "savings"
         int         sortOrder = -1;  // -1 = auto (use default sort)
+        bool        mining = false;
     };
     const AddressMeta& getAddressMeta(const std::string& addr) const {
         static const AddressMeta empty{};
@@ -162,6 +163,20 @@ public:
     void setAddressSortOrder(const std::string& addr, int order) {
         address_meta_[addr].sortOrder = order;
     }
+    bool isMiningAddress(const std::string& addr) const {
+        auto it = address_meta_.find(addr);
+        return it != address_meta_.end() && it->second.mining;
+    }
+    void setMiningAddress(const std::string& addr, bool mining) {
+        address_meta_[addr].mining = mining;
+    }
+    std::set<std::string> getMiningAddresses() const {
+        std::set<std::string> addresses;
+        for (const auto& [addr, meta] : address_meta_) {
+            if (meta.mining) addresses.insert(addr);
+        }
+        return addresses;
+    }
     int getNextSortOrder() const {
         int mx = -1;
         for (const auto& [k, v] : address_meta_)