chore(compose): parameterize searxng host port via SEARXNG_HOST_PORT (#6598)

The searxng host binding was hardcoded to 127.0.0.1:8080 in all three
compose files, which collides with other stacks that legitimately use
8080 (e.g. a local llama.cpp server). Parameterize it the same way the
odysseus UI port already works:

  ports:
    - "127.0.0.1:${SEARXNG_HOST_PORT:-8080}:8080"

Default unchanged (8080). The UI->searxng connection uses the container
port over the docker network (SEARXNG_INSTANCE=http://searxng:8080), so
no other change is needed.

Co-authored-by: Alexandre Teixeira <general@alexandreteixeira.dev>

docker-compose.gpu-amd.yml

@@ -165,7 +165,7 @@ services:
         /usr/local/searxng/.venv/bin/python /tmp/migrate-searxng-settings.py /etc/searxng/settings.yml || true
         exec /usr/local/searxng/entrypoint.sh
     ports:
-      - "127.0.0.1:8080:8080"
+      - "127.0.0.1:${SEARXNG_HOST_PORT:-8080}:8080"
     volumes:
       - searxng-data:/etc/searxng
       - ./config/searxng/settings.yml:/tmp/searxng-settings.yml.template:ro,z

docker-compose.gpu-nvidia.yml

@@ -168,7 +168,7 @@ services:
         /usr/local/searxng/.venv/bin/python /tmp/migrate-searxng-settings.py /etc/searxng/settings.yml || true
         exec /usr/local/searxng/entrypoint.sh
     ports:
-      - "127.0.0.1:8080:8080"
+      - "127.0.0.1:${SEARXNG_HOST_PORT:-8080}:8080"
     volumes:
       - searxng-data:/etc/searxng
       - ./config/searxng/settings.yml:/tmp/searxng-settings.yml.template:ro,z

docker-compose.yml

@@ -146,7 +146,7 @@ services:
         /usr/local/searxng/.venv/bin/python /tmp/migrate-searxng-settings.py /etc/searxng/settings.yml || true
         exec /usr/local/searxng/entrypoint.sh
     ports:
-      - "127.0.0.1:8080:8080"
+      - "127.0.0.1:${SEARXNG_HOST_PORT:-8080}:8080"
     volumes:
       - searxng-data:/etc/searxng
       - ./config/searxng/settings.yml:/tmp/searxng-settings.yml.template:ro,z