fix(wallets): folder picker fills the window; footer no longer clipped

The picker used a fixed-height card whose budget under-counted ImGui's
inter-item spacing, so on larger windows / at 150% DPI the footer buttons
overflowed the card's clip rect and got cut off.

Rework it as a flex column: the card takes ~82% of the viewport height (like
the console command-reference modal) and the directory list fills whatever
space is left above a reserved footer block. The status line + Scan/Cancel
buttons are now always pinned at the bottom and visible at any window size or
DPI, and the browsing area is generous instead of a cramped fixed row count.
Verified headless at 100% + 150%.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/ui/windows/folder_picker.h

@@ -63,25 +63,20 @@ public:
         ImFont* icoFont = Type().iconSmall();
         ImFont* metaFont = Type().caption();
 
-        // ---- Fixed-height card sized to a stable row budget (no auto-height feedback) ----------
+        const float rowH    = rowFont->LegacySize + Layout::spacingMd();
-        const int   kVisRows = 9;
-        const float rowH   = rowFont->LegacySize + Layout::spacingMd();
         const float listPad = Layout::spacingXs();
-        const float listH  = kVisRows * rowH + listPad * 2.0f;
 
-        const float headH   = Type().h6()->LegacySize + Layout::spacingXs();
+        // The card takes a generous share of the window (a file browser wants room) — not a fixed
-        const float pathH   = ImGui::GetFrameHeight() + Layout::spacingSm();
+        // row count. The list inside FLEXES to fill whatever height is left above the footer, so the
-        const float statusH = metaFont->LegacySize + Layout::spacingXs();
+        // footer is always pinned + visible and nothing clips, at any window size or DPI.
-        const float footH   = Layout::spacingSm() + 1.0f + Layout::spacingSm()
+        const float vpH   = ImGui::GetMainViewport()->Size.y;
-                            + ImGui::GetFrameHeightWithSpacing();
+        const float cardH = (vpH * 0.82f) / dp;   // logical; the framework re-applies dp + caps at vp-32
-        const float padV    = 52.0f;
-        const float cardH   = (headH + pathH + listH + statusH + footH + padV) / dp;
 
         OverlayDialogSpec ov;
         ov.title      = TR("picker_title");
         ov.p_open     = &s_open;
         ov.style      = OverlayStyle::BlurFloat;
-        ov.cardWidth  = 720.0f;
+        ov.cardWidth  = 760.0f;
         ov.cardHeight = cardH;
         ov.idSuffix   = "folderpicker";
         if (!BeginOverlayDialog(ov)) return;
@@ -145,6 +140,15 @@ public:
         ImGui::Dummy(ImVec2(0, Layout::spacingSm()));
 
         // ---- Directory list: folders (clickable) then *.dat wallets present (informational) ----
+        // Flex: the list fills the space between the path bar and the footer block. Reserving a
+        // (slightly generous) footer height keeps the status line + buttons pinned and never clipped.
+        const ImGuiStyle& gstyle = ImGui::GetStyle();
+        const float footerBlockH = Layout::spacingXs() + metaFont->LegacySize          // status line
+                                 + Layout::spacingSm() + 1.0f + Layout::spacingSm()     // separator block
+                                 + ImGui::GetFrameHeight()                              // footer buttons
+                                 + 6.0f * gstyle.ItemSpacing.y;                         // inter-item gaps
+        float listH = ImGui::GetContentRegionAvail().y - footerBlockH;
+        listH = std::max(listH, rowH * 3.0f + listPad * 2.0f);
         ImGui::PushStyleVar(ImGuiStyleVar_WindowPadding, ImVec2(listPad, listPad));
         ImGui::PushStyleColor(ImGuiCol_ChildBg, WithAlpha(OnSurface(), 20));
         ImGui::BeginChild("##pickerList", ImVec2(fullW, listH), true);