fix: SearXNG startup + update README logo and favicon

- Fix SearXNG limiter.toml directory issue by creating file at container
  startup via entrypoint command (rm -rf then recreate)
- Update README to use logo.svg instead of logo.png
- Redesign favicon.svg to match main logo style:
  - Same gold-to-green gradient background
  - Line gradient from white to green
  - Glow effect on chart line
  - Decorative dots at data points
  - Green arrow indicator

docker-compose.yml

@@ -62,7 +62,19 @@ services:
       - SEARXNG_SECRET=priceflow-searxng-secret
     volumes:
       - ./searxng/settings.yml:/etc/searxng/settings.yml:ro
-      - ./searxng/limiter.toml:/etc/searxng/limiter.toml:ro
+    entrypoint: /bin/sh
+    command:
+      - -c
+      - |
+        rm -rf /etc/searxng/limiter.toml
+        cat > /etc/searxng/limiter.toml << 'EOF'
+        [botdetection.ip_limit]
+        link_token = false
+        [botdetection.ip_lists]
+        pass_ip = ["0.0.0.0/0", "127.0.0.0/8", "172.16.0.0/12", "192.168.0.0/16", "10.0.0.0/8", "::/0"]
+        block_ip = []
+        EOF
+        exec /sbin/tini -- /usr/local/searxng/dockerfiles/docker-entrypoint.sh
     networks:
       - nginx_default