Reduce redundant RPC calls in periodic refresh cycle

- Remove getinfo from refreshMiningInfo slow path; daemon_version,
  protocol_version, and p2p_port are static per connection (set in
  onConnected). Move longestchain/notarized into refreshBalance's
  existing getblockchaininfo callback.

- Remove refreshMiningInfo from refreshData(); it already runs on
  the 1-second fast_refresh_timer_ independently.

- Make refreshAddresses demand-driven via addresses_dirty_ flag;
  only re-fetch when a new address is created or a send completes,
  not unconditionally every 5 seconds.

- Gate refreshPeerInfo to only run when the Peers tab is active.

- Skip duplicate getwalletinfo on connect; onConnected() already
  prefetches it for immediate lock-screen display, so suppress the
  redundant call in the first refreshData() cycle.

Steady-state savings: ~8 fewer RPC calls per 5-second cycle
(from ~12+ down to ~4-5 in the common case).

src/app.h

@@ -422,6 +422,10 @@ private:
     // P4: Incremental transaction cache
     int last_tx_block_height_ = -1;  // block height at last full tx fetch
 
+    // Dirty flags for demand-driven refresh
+    bool addresses_dirty_ = true;           // true → refreshAddresses() will run
+    bool encryption_state_prefetched_ = false; // suppress duplicate getwalletinfo on connect
+
     // First-run wizard state
     WizardPhase wizard_phase_ = WizardPhase::None;
     std::unique_ptr<util::Bootstrap> bootstrap_;