Function drawActionButton

switch/source/MainScreen.cpp:165–196

An action button: filled accent (Backup/Send) or outlined (Restore/Receive), label + the shoulder-key system glyph centered as a group. An empty `key` draws the label alone (the wireless buttons are touch-only — every face/shoulder button is already bound). `enabled` false greys the button out (faint fill, muted text) for a shown-but-inactive action, e.g. Send while a non-sendable row is highlight

    // greys the button out (faint fill, muted text) for a shown-but-inactive
    // action, e.g. Send while a non-sendable row is highlighted.
    void drawActionButton(int x, int y, const std::string& label, const std::string& key, bool filled, int w = BTN_W, bool enabled = true)
    {
        // Square buttons (radius 0), matching the 3DS action buttons and the
        // squared rail / rows.
        if (!enabled) {
            Shapes::fillRound(x, y, w, BTN_H, 0, COLOR_FILL1);
        }
        else if (filled) {
            Shapes::fillRound(x, y, w, BTN_H, 0, COLOR_ACCENT);
        }
        else {
            Shapes::strokeRound(x, y, w, BTN_H, 0, 2, COLOR_STROKE3);
        }

        const Color fg = !enabled ? COLOR_TEXT3 : (filled ? COLOR_WHITE : COLOR_TEXT);

        u32 lw, lh;
        Gfx::GetTextDimensions(16, label.c_str(), &lw, &lh);
        if (key.empty()) {
            Gfx::DrawText(16, x + (w - (int)lw) / 2, y + (BTN_H - (int)lh) / 2, fg, label.c_str());
            return;
        }

        const std::string glyph = UiKit::buttonGlyph(key);
        u32 gw, gh;
        Gfx::GetTextDimensions(ACTION_GLYPH_SIZE, glyph.c_str(), &gw, &gh);
        const int gap   = 10;
        const int group = (int)lw + gap + (int)gw;
        const int sx    = x + (w - group) / 2;
        Gfx::DrawText(16, sx, y + (BTN_H - (int)lh) / 2, fg, label.c_str());
        Gfx::DrawText(ACTION_GLYPH_SIZE, sx + (int)lw + gap, y + (BTN_H - (int)gh) / 2, fg, glyph.c_str());
    }

    // Maps a failed network send to a user-facing message (mirrors the 3DS
    // OutcomeMessages::sendError). EmptyBackup and Cancelled are handled by the