feat: gráficos de área en la pestaña Sistema

graph() admite ahora relleno translúcido por serie (s.fill). Las nueve
gráficas de Sistema usan área para mejor legibilidad; la pestaña Red
mantiene líneas porque superpone dos series (down/up).

lua/widget.lua

@@ -219,7 +219,8 @@ local function bar(cr, x, y, w, h, frac, c)
     setcol(cr, c);                rrect(cr, x, y, math.max(2, w * frac), h, 3); cairo_fill(cr)
 end
 
--- Grafico de linea sobre un panel redondeado ---------------------------------
+-- Grafico sobre un panel redondeado. Cada serie con s.fill=true se dibuja como
+-- area (relleno translucido) ademas de la linea; si no, solo linea.
 local function graph(cr, x, y, w, h, series)
     setcol(cr, COL.panel); rrect(cr, x, y, w, h, 4); cairo_fill(cr)
     -- Maximo comun a todas las series (fijo si se indica)
@@ -232,12 +233,19 @@ local function graph(cr, x, y, w, h, series)
         end
     end
     for _, s in ipairs(series) do
-        cairo_set_line_width(cr, 1.3); setcol(cr, s.c)
         local n = #s.data
+        local function px(i) return x + (i - 1) / (n - 1) * w end
+        local function py(i) return y + h - (s.data[i] / maxv) * (h - 4) - 2 end
+        if s.fill then
+            cairo_move_to(cr, px(1), y + h)
+            for i = 1, n do cairo_line_to(cr, px(i), py(i)) end
+            cairo_line_to(cr, px(n), y + h)
+            cairo_close_path(cr)
+            setcol(cr, s.c, 0.25); cairo_fill(cr)
+        end
+        cairo_set_line_width(cr, 1.3); setcol(cr, s.c)
         for i = 1, n do
-            local px = x + (i - 1) / (n - 1) * w
+            if i == 1 then cairo_move_to(cr, px(i), py(i)) else cairo_line_to(cr, px(i), py(i)) end
-            local py = y + h - (s.data[i] / maxv) * (h - 4) - 2
-            if i == 1 then cairo_move_to(cr, px, py) else cairo_line_to(cr, px, py) end
         end
         cairo_stroke(cr)
     end
@@ -341,34 +349,34 @@ local function draw_sys(cr)
     -- CPU
     local gh = row("CPU " .. math.floor(num("${cpu cpu0}")) .. "%",
                    str("${freq_g}") .. "GHz  " .. cputemp .. "°C", COL.teal, 26)
-    graph(cr, x, y, gw, gh, { { data = hist.cpu, c = COL.green, max = 100 } }); y = y + gh + 4
+    graph(cr, x, y, gw, gh, { { data = hist.cpu, c = COL.green, max = 100, fill = true } }); y = y + gh + 4
 
     -- RAM
     gh = row("RAM " .. math.floor(num("${memperc}")) .. "%",
              str("${mem}") .. " / " .. str("${memmax}"), COL.green, 26)
-    graph(cr, x, y, gw, gh, { { data = hist.ram, c = COL.green, max = 100 } }); y = y + gh + 4
+    graph(cr, x, y, gw, gh, { { data = hist.ram, c = COL.green, max = 100, fill = true } }); y = y + gh + 4
 
     -- CPU TEMP
     gh = row("CPU TEMP " .. cputemp .. "°C", "", COL.yellow, 20)
-    graph(cr, x, y, gw, gh, { { data = hist.cputemp, c = COL.yellow, max = 100 } }); y = y + gh + 4
+    graph(cr, x, y, gw, gh, { { data = hist.cputemp, c = COL.yellow, max = 100, fill = true } }); y = y + gh + 4
 
     -- GPU
     gh = row("GPU " .. str("${execi 2 " .. MET .. " gpu_util}") .. "%",
              gputemp .. "°C", COL.cyan, 26)
-    graph(cr, x, y, gw, gh, { { data = hist.gputil, c = COL.cyan, max = 100 } }); y = y + gh + 4
+    graph(cr, x, y, gw, gh, { { data = hist.gputil, c = COL.cyan, max = 100, fill = true } }); y = y + gh + 4
 
     -- GPU TEMP
     gh = row("GPU TEMP " .. gputemp .. "°C", "", COL.yellow, 20)
-    graph(cr, x, y, gw, gh, { { data = hist.gputemp, c = COL.yellow, max = 100 } }); y = y + gh + 4
+    graph(cr, x, y, gw, gh, { { data = hist.gputemp, c = COL.yellow, max = 100, fill = true } }); y = y + gh + 4
 
     -- VRAM
     gh = row("VRAM " .. str("${execi 2 " .. MET .. " gpu_memp}") .. "%",
              str("${execi 2 " .. MET .. " gpu_memi}"), COL.purple, 26)
-    graph(cr, x, y, gw, gh, { { data = hist.vram, c = COL.purple, max = 100 } }); y = y + gh + 4
+    graph(cr, x, y, gw, gh, { { data = hist.vram, c = COL.purple, max = 100, fill = true } }); y = y + gh + 4
 
     -- DISK I/O
     gh = row("DISK I/O", str("${diskio}"), COL.orange, 26)
-    graph(cr, x, y, gw, gh, { { data = hist.diskio, c = COL.purple } }); y = y + gh + 6
+    graph(cr, x, y, gw, gh, { { data = hist.diskio, c = COL.purple, fill = true } }); y = y + gh + 6
 
     -- Uso de discos
     text(cr, x, y + 10, "USO DE DISCOS", COL.snow, 10, true); y = y + 16