fix(send/receive): unify card width, justify receive footer, fix recipient-row button height/clip/glyph

Send and Receive are now consistent in layout, and the Send recipient row's buttons
render correctly.

Card envelope (Send ⇄ Receive consistency):
- Add Layout::mainComposeCardBox(availW) — a single shared source for the compose card's
  width + centering (fill the available column up to content-max-width, then center). Both
  tabs derive their card from it, so they can't drift again. Previously Send capped at
  760dp and Receive at 860dp, so the Send card rendered ~150px narrower on any window wider
  than ~860dp; now they fill available width identically.

Receive:
- Justify the footer buttons edge-to-edge (equal shares over the live count) instead of
  left-clustering with dead space, matching Send's full-width footer rhythm.
- Build the address-dropdown preview to the combo's real pixel width so the trailing
  balance ("— 12.00000000 DRGX") no longer hard-clips at 150% (was char-count truncation).

Send recipient row (input | Paste | contacts-icon):
- Pin the contacts icon button to the frame height so the larger iconMed font doesn't
  auto-size it taller than Paste/the input.
- Reserve the real ItemSpacing.x gaps (not the smaller spacingSm token) so the row no
  longer overshoots the card and clips the icon's right border.

draw_helpers (root cause, app-wide):
- TactileButton's icon path measured/drew the label INCLUDING the "##id" suffix (which
  CalcTextSizeA/AddText don't strip the way ImGui's text render does), shoving the glyph
  off-center-left. Strip at "##" before measuring/drawing. Corrects any icon button that
  passes an explicit size and a "##id" label; no-op for labels without "##".

Verified via headless sweeps at 1.0x and 1.5x, plus a real 3800px-wide render (both cards
byte-identical at L=1174/R=2773). ctest 1/1.

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

src/ui/material/draw_helpers.h

@@ -544,11 +544,16 @@ inline bool TactileButton(const char* label, const ImVec2& size = ImVec2(0, 0),
     ImVec2 bMin = ImGui::GetItemRectMin();
     ImVec2 bMax = ImGui::GetItemRectMax();
     
-    // For icon fonts, manually draw centered icon after getting button rect
+    // For icon fonts, manually draw centered icon after getting button rect. Measure/draw only the
+    // VISIBLE label (up to the "##id" separator): CalcTextSizeA/AddText don't strip "##" the way
+    // ImGui's own text render does, so an id suffix like "##pickContact" would inflate textSz and
+    // shove the glyph left off-center (and try to draw the notdef id chars).
     if (isIconFont && size.x > 0 && size.y > 0) {
-        ImVec2 textSz = useFont->CalcTextSizeA(useFont->LegacySize, FLT_MAX, 0, label);
+        const char* labelEnd = label;
+        while (*labelEnd && !(labelEnd[0] == '#' && labelEnd[1] == '#')) ++labelEnd;
+        ImVec2 textSz = useFont->CalcTextSizeA(useFont->LegacySize, FLT_MAX, 0, label, labelEnd);
         ImVec2 textPos(bMin.x + (size.x - textSz.x) * 0.5f, bMin.y + (size.y - textSz.y) * 0.5f);
-        dl->AddText(useFont, useFont->LegacySize, textPos, ImGui::GetColorU32(ImGuiCol_Text), label);
+        dl->AddText(useFont, useFont->LegacySize, textPos, ImGui::GetColorU32(ImGuiCol_Text), label, labelEnd);
     }
     
     float rounding = ImGui::GetStyle().FrameRounding;