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/transaction_details_dialog.cpp

@@ -124,7 +124,7 @@ void TransactionDetailsDialog::render(App* app)
         ImGui::SetNextItemWidth(txidInput.width);  // negative = fill, reserving |width| px for the Copy button (a content-region margin, not raw px — must NOT be dpi-scaled)
         ImGui::InputText("##TxID", txid_buf, sizeof(txid_buf), ImGuiInputTextFlags_ReadOnly);
         ImGui::SameLine();
-        if (material::StyledButton("Copy##TxID", ImVec2(copyBtn.width, 0), S.resolveFont(copyBtn.font))) {
+        if (material::StyledButton((std::string(TR("grpb_copy")) + "##TxID").c_str(), ImVec2(copyBtn.width, 0), S.resolveFont(copyBtn.font))) {
             ImGui::SetClipboardText(tx.txid.c_str());
         }
 
@@ -150,7 +150,7 @@ void TransactionDetailsDialog::render(App* app)
                 ImGui::InputText("##Address", addr_buf, sizeof(addr_buf), ImGuiInputTextFlags_ReadOnly);
             }
             ImGui::SameLine();
-            if (material::StyledButton("Copy##Addr", ImVec2(copyBtn.width, 0), S.resolveFont(copyBtn.font))) {
+            if (material::StyledButton((std::string(TR("grpb_copy")) + "##Addr").c_str(), ImVec2(copyBtn.width, 0), S.resolveFont(copyBtn.font))) {
                 ImGui::SetClipboardText(tx.address.c_str());
             }
         }