refactor(ui): extract shared ProgressBar / CopyableTextOverlay / DrawPill helpers

UI-standardization audit: three draw patterns were copy-pasted across tabs and
dialogs. Promote each to a material:: helper and adopt at every verbatim site.
Output is pixel-identical (same colors/geometry threaded through as params).

- material::DrawProgressBar / ProgressBar — replaces 3 byte-identical rounded
  fill bars in the daemon/xmrig/bootstrap download dialogs.
- material::CopyableTextOverlay — the click-to-copy affordance (hit button +
  hand cursor + tooltip + hover underline + clipboard) shared by the peers
  best-block hash and the 3 mining stats (difficulty/block/address). Returns
  "copied this frame" so callers keep their own toast (no ui-layer dependency).
- material::DrawPill / PillSize — rounded bg + optional border + inset text
  badge, shared by the explorer status pill, the market Z/T chip, and the
  network official/custom tag.

Divergent one-offs left in place (transactions status pills use schema rounding
around pre-positioned multi-line text; the mining filter-pill is a button bg).

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

src/ui/windows/peers_tab.cpp

@@ -314,17 +314,10 @@ void RenderPeersTab(App* app)
                     // Click to copy full hash
                     ImVec2 hashSz = sub1->CalcTextSizeA(sub1->LegacySize, FLT_MAX, 0, truncHash.c_str());
                     ImVec2 savedCursor = ImGui::GetCursorScreenPos();
-                    ImGui::SetCursorScreenPos(ImVec2(cx, valY));
-                    ImGui::InvisibleButton("##BestBlockCopy", ImVec2(hashSz.x + Layout::spacingSm(), sub1->LegacySize + 2 * dp));
-                    if (ImGui::IsItemHovered()) {
-                        ImGui::SetMouseCursor(ImGuiMouseCursor_Hand);
-                        material::Tooltip("%s %s", TR("peers_click_copy"), hash.c_str());
-                        dl->AddLine(ImVec2(cx, valY + sub1->LegacySize + 1 * dp),
-                                    ImVec2(cx + hashSz.x, valY + sub1->LegacySize + 1 * dp),
-                                    WithAlpha(OnSurface(), 60), 1.0f * dp);
-                    }
-                    if (ImGui::IsItemClicked()) {
-                        ImGui::SetClipboardText(hash.c_str());
+                    std::string copyTip = std::string(TR("peers_click_copy")) + " " + hash;
+                    if (material::CopyableTextOverlay("##BestBlockCopy", ImVec2(cx, valY), hashSz,
+                                                      sub1->LegacySize, hash.c_str(), copyTip.c_str(),
+                                                      ImVec2(Layout::spacingSm(), 2 * dp))) {
                         ui::Notifications::instance().info(TR("peers_hash_copied"));
                     }
                     ImGui::SetCursorScreenPos(savedCursor);