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/mining_controls.cpp

@@ -153,7 +153,12 @@ void RenderMiningControls(App* app, const WalletState& state, const MiningInfo&
                     }
                 };
                 ImFont* stepFont  = Type().iconSmall();
-                const float fieldH = capFont->LegacySize + 6.0f * dp;
+                // Match the -/+ button height to the InputInt's actual frame height (GetFrameHeight ==
+                // fontSize + 2*FramePadding.y, evaluated with the same font/style the input renders with,
+                // since nothing pushes a font between here and the InputInt below). This keeps the buttons
+                // the SAME height as the number box and top-aligned with it at sy — previously fieldH was
+                // capFont+6px, shorter than the box, so they sat misaligned.
+                const float fieldH = ImGui::GetFrameHeight();
                 const float sideW  = fieldH;               // square -/+ buttons
                 const float fieldW = 46.0f * dp;
                 const float g      = 2.0f * dp;
@@ -544,7 +549,7 @@ void RenderMiningControls(App* app, const WalletState& state, const MiningInfo&
                                 s_benchConfirm = true;
                                 char msg[128];
                                 snprintf(msg, sizeof(msg),
-                                    "Benchmark takes ~%ds and interrupts mining. Click again to start.",
+                                    TR("grpc_benchmark_takes_secs"),
                                     (int)(s_benchmark.totalEstimatedSecs() + 0.5f));
                                 Notifications::instance().warning(msg);
                             } else {