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/sidebar.h

@@ -219,7 +219,7 @@ inline void DrawGlassCutout(ImDrawList* dl, ImVec2 mn, ImVec2 mx,
     float lineW = s_cc.lineW;
 
     // --- Outer glow pass: wider, softer dark edge on top-left ---
-    float glowExpand = s_cc.glowExpand;
+    float glowExpand = s_cc.glowExpand * Layout::dpiScale();
     int   glowA      = (int)s_cc.glowAlpha;
     float glowLineW  = s_cc.glowLineW;
     {
@@ -289,6 +289,7 @@ inline void DrawGlassBevelButton(ImDrawList* dl, ImVec2 mn, ImVec2 mx,
     // inner pass gives crisp bevel edge. All use AddRect with rounding so
     // every layer follows the rounded corners perfectly — no clip rects needed.
     {
+        const float dp = Layout::dpiScale();
         float cx = (mn.x + mx.x) * 0.5f;
         float cy = (mn.y + mx.y) * 0.5f;
 
@@ -304,7 +305,7 @@ inline void DrawGlassBevelButton(ImDrawList* dl, ImVec2 mn, ImVec2 mx,
 
         struct BevelPass { float expand; float lineW; float fadeStart; float fadeEnd; };
         BevelPass passes[] = {
-            { 0.5f, 0.75f, 0.30f, 0.55f }, // Outer glow (thin)
+            { 0.5f * dp, 0.75f, 0.30f, 0.55f }, // Outer glow (thin)
             { 0.0f, 0.75f, 0.38f, 0.58f }, // Inner crisp bevel
         };
 
@@ -387,7 +388,7 @@ inline void DrawGlassBevelButton(ImDrawList* dl, ImVec2 mn, ImVec2 mx,
         }
     }
     if (depth > s_ic.threshold) {
-        float baseInset = s_ic.inset;
+        float baseInset = s_ic.inset * Layout::dpiScale();
         int shadowMax = (int)(s_ic.maxAlpha * depth);
         float fadeRatio = s_ic.fadeRatio;
         float bW = mx.x - mn.x - baseInset * 2.0f;
@@ -487,7 +488,7 @@ inline bool RenderSidebar(NavPage& current, float sidebarWidth, float contentHei
     float fixedH = stripH;  // collapse strip
     for (int i = 0; i < (int)NavPage::Count_; ++i)
         if (IsNavPageVisible(kNavItems[i].page) && kNavItems[i].section_label && showLabels)
-            fixedH += olFsz + 2.0f + sectionLabelPadBot;  // section label + pad below
+            fixedH += olFsz + 2.0f * dp + sectionLabelPadBot;  // section label + pad below
     fixedH += bottomPadding + stripH;  // exit area
 
     float baseFlexH = baseNavGap;
@@ -525,7 +526,7 @@ inline bool RenderSidebar(NavPage& current, float sidebarWidth, float contentHei
             if (showLabels) {
                 curY += sectionGap;
                 if (nSectionLabels < 4) sectionLabelY[nSectionLabels++] = curY;
-                curY += olFsz + 2.0f + sectionLabelPadBot;
+                curY += olFsz + 2.0f * dp + sectionLabelPadBot;
             } else {
                 curY += sectionGap * 0.4f;
                 if (nSeparators < 4) separatorY[nSeparators++] = curY;
@@ -653,7 +654,7 @@ inline bool RenderSidebar(NavPage& current, float sidebarWidth, float contentHei
                 fx.drawShimmer(dl, indMin, indMax, btnRnd);
                 fx.drawGradientBorderShift(dl, indMin, indMax, btnRnd);
             }
-            DrawGlassCutout(dl, indMin, indMax, btnRnd, 1.5f);
+            DrawGlassCutout(dl, indMin, indMax, btnRnd, 1.5f * dp);
             DrawGlassBevelButton(dl, indMin, indMax, btnRnd, btnDepth, 18);
             buttonRects.push_back({indMin, indMax, btnRnd});
         }
@@ -684,7 +685,6 @@ inline bool RenderSidebar(NavPage& current, float sidebarWidth, float contentHei
             bool itemHasBadge =
                 (item.page == NavPage::History && status.unconfirmedTxCount > 0) ||
                 (item.page == NavPage::Mining && status.miningActive) ||
-                (item.page == NavPage::Peers && status.peerCount > 0) ||
                 (item.page == NavPage::Chat && status.chatUnreadCount > 0);
             float badgeReserve = 0.0f;
             if (itemHasBadge) {
@@ -732,8 +732,6 @@ inline bool RenderSidebar(NavPage& current, float sidebarWidth, float contentHei
                 badgeCol = Warning(); badgeTextCol = OnWarning();
             } else if (item.page == NavPage::Mining && status.miningActive) {
                 dotOnly = true; badgeCol = Success();
-            } else if (item.page == NavPage::Peers && status.peerCount > 0) {
-                badgeCount = status.peerCount;
             } else if (item.page == NavPage::Chat && status.chatUnreadCount > 0) {
                 badgeCount = status.chatUnreadCount;
             }