Remove duplicate MOTD, source bashrc after install

- System MOTD already shows banner, bashrc one was redundant
- Source bashrc immediately after copying for instant effect

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

rpi/setup.sh

@@ -309,6 +309,7 @@ echo "  Added stegasoo to PATH"
 if [ -f "$INSTALL_DIR/rpi/skel/.bashrc" ]; then
     if ! grep -q "Stegasoo Pi" ~/.bashrc 2>/dev/null; then
         cp "$INSTALL_DIR/rpi/skel/.bashrc" ~/.bashrc
+        source ~/.bashrc 2>/dev/null || true
         echo "  Installed custom .bashrc"
     else
         echo "  Custom .bashrc already installed"