Branding: logo propio y favicon

Agrega logo.svg (squircle violeta/plum con C y punto mint), favicon SVG,
favicon PNG 32x32 y apple-touch-icon 180. Reemplaza el badge externo de la OCA
en el header y el footer por el logo propio.

img/favicon.svg

@@ -0,0 +1,11 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 96 96" role="img" aria-label="OCA Paraguay">
+  <defs>
+    <linearGradient id="ocaPyF" x1="0" y1="0" x2="1" y2="1">
+      <stop offset="0" stop-color="#6C4CE0"/>
+      <stop offset="1" stop-color="#714B67"/>
+    </linearGradient>
+  </defs>
+  <rect width="96" height="96" rx="22" fill="url(#ocaPyF)"/>
+  <path d="M62 25 A26.5 26.5 0 1 0 62 71" fill="none" stroke="#ffffff" stroke-width="12" stroke-linecap="round"/>
+  <circle cx="72" cy="48" r="8.5" fill="#16C79A"/>
+</svg>

img/logo.svg

@@ -0,0 +1,11 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 96 96" role="img" aria-label="OCA Paraguay">
+  <defs>
+    <linearGradient id="ocaPyG" x1="0" y1="0" x2="1" y2="1">
+      <stop offset="0" stop-color="#6C4CE0"/>
+      <stop offset="1" stop-color="#714B67"/>
+    </linearGradient>
+  </defs>
+  <rect width="96" height="96" rx="24" fill="url(#ocaPyG)"/>
+  <path d="M61.5 25.5 A26 26 0 1 0 61.5 70.5" fill="none" stroke="#ffffff" stroke-width="9" stroke-linecap="round"/>
+  <circle cx="71" cy="48" r="7.5" fill="#16C79A"/>
+</svg>