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/faq_content.h

@@ -0,0 +1,41 @@
+// DragonX Wallet - ImGui Edition
+// Copyright 2024-2026 The Hush Developers
+// Released under the GPLv3
+//
+// FAQ content model. The FAQ screen is data-driven: this header exposes the two
+// top-level groups (Wallet, Daemon) as ordered lists of subcategories, each a list
+// of question/answer entries. Every string is an i18n KEY (looked up with TR at
+// render time), so wording + translations live in src/util/i18n.cpp + res/lang/*.json
+// and never require touching UI code. Add a Q&A by appending a {qKey,aKey} pair here
+// and its two strings to loadBuiltinEnglish().
+
+#pragma once
+
+#include <vector>
+
+namespace dragonx {
+namespace ui {
+namespace faq {
+
+// One question and its answer, both i18n keys. The answer may contain "\n\n"
+// paragraph breaks; it is rendered wrapped. Keep answers free of printf specifiers
+// (%d/%s/…) — the i18n layer rejects translations whose format signature drifts.
+struct FaqEntry {
+    const char* questionKey;
+    const char* answerKey;
+};
+
+// A named group of questions. titleKey is an i18n key for the subcategory header.
+struct FaqSubcategory {
+    const char* titleKey;
+    std::vector<FaqEntry> entries;
+};
+
+// The two top-level groups. daemonFaq() is full-node material and is only shown when
+// the build supports full-node lifecycle actions (see App::supportsFullNodeLifecycleActions()).
+const std::vector<FaqSubcategory>& walletFaq();
+const std::vector<FaqSubcategory>& daemonFaq();
+
+} // namespace faq
+} // namespace ui
+} // namespace dragonx