feat(ui): in-app FAQ, DPI-scaling audit fixes, mining/stratum polish + localize strings

Bundles the session's UI work (the touched files carry several of these
changes together, so they are committed as one coherent UI batch):

- FAQ: new RenderFaqDialog + data-driven faq_content, opened from a
  status-bar "?" (and the Windows title bar), styled like the Wallets
  modal with search, Wallet/Daemon tabs, and smooth scroll.
- DPI/font-scale audit: multiply hand-drawn absolute geometry by
  Layout::dpiScale() across ~30 files so nothing renders native-size at
  HiDPI / font_scale 1.5 (verified with a full sweep at 1.5x).
- Mining: chart now fills the horizontal space; thread stepper +/- buttons
  match the input-box height; move the stratum-host toggle into
  Node & Security (v1.3.0+).
- Settings: fix the auto-shield status text overlapping the grid.
- Sidebar: drop the peer-count badge on the Network button.
- i18n: wrap 193 hardcoded literals with TR() (keys/translations added in
  the preceding i18n commit), so the security/PIN/lock flow, seed-backup
  wizard, and witness-rebuild dialog localize.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/ui/windows/block_info_dialog.cpp

@@ -59,7 +59,7 @@ static void handleBlockResponseUnified(const json& result, const std::string& er
     s_loading = false;
     
     if (!error.empty()) {
-        s_error = "Error: " + error;
+        s_error = std::string(TR("grpa_error_prefix")) + error;
         return;
     }
     
@@ -84,7 +84,7 @@ static void handleBlockResponseUnified(const json& result, const std::string& er
         
         s_has_data = true;
     } else {
-        s_error = "Invalid response from daemon";
+        s_error = TR("grpa_invalid_response_from_daemon");
     }
 }
 
@@ -125,7 +125,7 @@ void BlockInfoDialog::render(App* app)
         
         // Current block info
         if (state.sync.blocks > 0) {
-            ImGui::TextDisabled("(Current: %d)", state.sync.blocks);
+            ImGui::TextDisabled(TR("grpa_current_block_paren"), state.sync.blocks);
         }
         
         ImGui::SameLine();
@@ -152,7 +152,7 @@ void BlockInfoDialog::render(App* app)
                         rpc::RPCClient::TraceScope trace("Explorer / Block info");
                         auto hashResult = rpc->call("getblockhash", {height});
                         if (!hashResult.is_string()) {
-                            error = "unexpected getblockhash result";
+                            error = TR("grpa_unexpected_getblockhash_result");
                         } else {
                             block = rpc->call("getblock", {hashResult.get<std::string>()});
                         }