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/app_sweep.cpp

@@ -310,6 +310,8 @@ void App::buildSweepCatalog()
         [](App& a) { ui::BootstrapDownloadDialog::show(&a); }, [](App&) { ui::BootstrapDownloadDialog::hide(); });
     add("modal-backup", ui::NavPage::Overview,
         [](App& a) { a.show_backup_ = true; }, [](App& a) { a.show_backup_ = false; a.backup_status_.clear(); });
+    add("modal-faq", ui::NavPage::Overview,
+        [](App& a) { a.show_faq_ = true; }, [](App& a) { a.show_faq_ = false; });
     // Encrypt-wallet dialog — the redesigned passphrase-entry phase (never fires the async encrypt).
     add("modal-encrypt", ui::NavPage::Settings,
         [](App& a) { a.encrypt_dialog_phase_ = EncryptDialogPhase::PassphraseEntry; a.show_encrypt_dialog_ = true; },
@@ -708,9 +710,22 @@ void App::startSweepImpl(bool full)
     if (sweep_current_theme_only_)
         sweep_skins_.assign(1, ui::schema::SkinManager::instance().activeSkinId());
 
+    // DEV/TEST hook (dormant unless the env is set): DRAGONX_SWEEP_ONLY="send,receive" restricts the
+    // sweep to the named surfaces and the dark skin, so a slow large-window run captures just the tab
+    // under review instead of all surfaces x every skin.
+    const char* sweepOnly = std::getenv("DRAGONX_SWEEP_ONLY");
+    std::string sweepOnlyStr = sweepOnly ? sweepOnly : "";
+    if (!sweepOnlyStr.empty()) sweep_skins_.assign(1, std::string("dark"));
+
     sweep_full_ = full;
     if (full) { capture_mode_ = true; installDemoWalletData(); }
     buildSweepCatalog();
+    if (!sweepOnlyStr.empty()) {
+        std::vector<SweepTarget> keep;
+        for (const auto& t : sweep_targets_)
+            if (sweepOnlyStr.find(t.name) != std::string::npos) keep.push_back(t);
+        sweep_targets_.swap(keep);
+    }
     if (sweep_targets_.empty()) { if (full) { clearDemoWalletData(); capture_mode_ = false; sweep_full_ = false; } return; }
 
     sweep_dir_ = full ? screenshotFullDir() : screenshotDir();