add logo and favicon

Signed-off-by: Tobias Erbshäußer <tobias@tesoft.dev>

frontend/public/assets/logo.svg

@@ -0,0 +1,70 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!-- Created with Inkscape (http://www.inkscape.org/) -->
+
+<svg
+   width="256"
+   height="256"
+   viewBox="0 0 256 256"
+   version="1.1"
+   id="svg1"
+   inkscape:version="1.4.2 (ebf0e940d0, 2025-05-08)"
+   sodipodi:docname="logo.svg"
+   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
+   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:svg="http://www.w3.org/2000/svg">
+  <sodipodi:namedview
+     id="namedview1"
+     pagecolor="#545454"
+     bordercolor="#000000"
+     borderopacity="0.25"
+     inkscape:showpageshadow="2"
+     inkscape:pageopacity="0.0"
+     inkscape:pagecheckerboard="0"
+     inkscape:deskcolor="#d1d1d1"
+     inkscape:document-units="px"
+     inkscape:zoom="2.0667789"
+     inkscape:cx="164.02335"
+     inkscape:cy="169.82949"
+     inkscape:window-width="1661"
+     inkscape:window-height="1071"
+     inkscape:window-x="26"
+     inkscape:window-y="23"
+     inkscape:window-maximized="0"
+     inkscape:current-layer="layer2" />
+  <defs
+     id="defs1" />
+  <g
+     inkscape:groupmode="layer"
+     id="layer2"
+     inkscape:label="Layer 2">
+    <rect
+       style="fill:#ffffff;stroke-width:2.34204"
+       id="rect2"
+       width="226"
+       height="45"
+       x="15"
+       y="15" />
+    <rect
+       style="fill:#ffffff;stroke-width:2.11578"
+       id="rect2-4-6"
+       width="50"
+       height="166"
+       x="80"
+       y="75" />
+    <rect
+       style="fill:#ffffff;stroke-width:1.52643"
+       id="rect2-0"
+       width="96"
+       height="45"
+       x="145"
+       y="196" />
+    <rect
+       style="fill:#ffffff;stroke-width:1.52642"
+       id="rect2-0-6"
+       width="96"
+       height="45"
+       x="145"
+       y="105.5" />
+  </g>
+</svg>