feat: add remote worker system for distributed translation

- Add remote translator worker (Docker) that connects via WebSocket
- Add backend Go handlers for remote worker CRUD (REST + WebSocket)
- Add frontend Admin panel for managing remote workers
- Add ProtectedRoute component to secure admin routes
- Add PostgreSQL schema for remote_workers table
- Fix duplicate Load function in config.go
- Fix frontend duplicate fetchStatus function
- Fix Dockerfiles missing go.sum (use go mod download + tidy)

Features:
- Workers connect to server via WebSocket (no ports needed)
- API key authentication per worker
- Job assigner automatically distributes translation jobs
- Worker status tracking (online/offline/disabled)
- Timeout handling for stuck jobs

Dockerfile.remote-worker

@@ -0,0 +1,50 @@
+FROM python:3.11-slim-bookworm
+
+SHELL ["/bin/bash", "-c"]
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    patchelf libpq-dev gcc git curl wget bash \
+    && rm -rf /var/lib/apt/lists/*
+
+ENV PYTHONUNBUFFERED=1 \
+    PIP_DISABLE_PIP_VERSION_CHECK=1 \
+    TOKENIZERS_PARALLELISM=false \
+    HF_HOME=/root/.cache/huggingface \
+    DEBIAN_FRONTEND=noninteractive
+
+WORKDIR /app
+
+COPY requirements.txt .
+RUN pip install --no-cache-dir --upgrade pip
+
+RUN pip install --no-cache-dir torch==2.1.0 torchvision==0.16.0 --index-url https://download.pytorch.org/whl/cpu
+
+RUN pip install --no-cache-dir \
+    ctranslate2==3.24.0 \
+    sentencepiece \
+    transformers==4.36.0 \
+    protobuf==3.20.3 \
+    "numpy<2" \
+    psycopg2-binary \
+    langdetect \
+    websocket-client
+
+RUN find /usr/local/lib/python3.11/site-packages/ctranslate2* \
+    -name "libctranslate2-*.so.*" -o -name "libctranslate2.so*" | \
+    xargs -I {} patchelf --clear-execstack {} || true
+
+COPY workers/ ./workers/
+COPY init-db/ ./init-db/
+COPY migrations/ ./migrations/
+
+ENV DB_HOST=db
+ENV DB_PORT=5432
+ENV DB_NAME=rss
+ENV DB_USER=rss
+ENV DB_PASS=x
+
+ENV WORKER_SERVER=ws://localhost:8080/ws/worker
+ENV CT2_DEVICE=cpu
+ENV CT2_COMPUTE_TYPE=int8
+
+CMD ["python", "-m", "workers.remote_translator_worker"]