Change default docker image to offline version

• Add lite verion docker image with tiktoken cache
• Update docs and build scripts

Dockerfile.lite

@@ -0,0 +1,102 @@
+# Frontend build stage
+FROM oven/bun:1 AS frontend-builder
+
+WORKDIR /app
+
+# Copy frontend source code
+COPY lightrag_webui/ ./lightrag_webui/
+
+# Build frontend assets for inclusion in the API package
+RUN cd lightrag_webui \
+    && bun install --frozen-lockfile \
+    && bun run build
+
+# Python build stage - using uv for package installation
+FROM ghcr.io/astral-sh/uv:python3.12-bookworm-slim AS builder
+
+ENV DEBIAN_FRONTEND=noninteractive
+ENV UV_SYSTEM_PYTHON=1
+ENV UV_COMPILE_BYTECODE=1
+
+WORKDIR /app
+
+# Install system dependencies required by some wheels
+RUN apt-get update \
+    && apt-get install -y --no-install-recommends \
+        curl \
+        build-essential \
+        pkg-config \
+    && rm -rf /var/lib/apt/lists/* \
+    && curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y
+
+ENV PATH="/root/.cargo/bin:/root/.local/bin:${PATH}"
+
+# Ensure shared data directory exists for uv caches
+RUN mkdir -p /root/.local/share/uv
+
+# Copy project metadata and sources
+COPY pyproject.toml .
+COPY setup.py .
+COPY uv.lock .
+
+# Install project dependencies (base + API extras) without the project to improve caching
+RUN uv sync --frozen --no-dev --extra api --no-install-project --no-editable
+
+# Copy project sources after dependency layer
+COPY lightrag/ ./lightrag/
+
+# Include pre-built frontend assets from the previous stage
+COPY --from=frontend-builder /app/lightrag/api/webui ./lightrag/api/webui
+
+# Sync project in non-editable mode and ensure pip is available for runtime installs
+RUN uv sync --frozen --no-dev --extra api --no-editable \
+    && /app/.venv/bin/python -m ensurepip --upgrade
+
+# Prepare tiktoken cache directory and pre-populate tokenizer data
+# Ignore exit code 2 which indicates assets already cached
+RUN mkdir -p /app/data/tiktoken \
+    && uv run lightrag-download-cache --cache-dir /app/data/tiktoken || status=$?; \
+    if [ -n "${status:-}" ] && [ "$status" -ne 0 ] && [ "$status" -ne 2 ]; then exit "$status"; fi
+
+# Final stage
+FROM python:3.12-slim
+
+WORKDIR /app
+
+# Install uv for package management
+COPY --from=ghcr.io/astral-sh/uv:latest /uv /usr/local/bin/uv
+
+ENV UV_SYSTEM_PYTHON=1
+
+# Copy installed packages and application code
+COPY --from=builder /root/.local /root/.local
+COPY --from=builder /app/.venv /app/.venv
+COPY --from=builder /app/lightrag ./lightrag
+COPY pyproject.toml .
+COPY setup.py .
+COPY uv.lock .
+
+# Ensure the installed scripts are on PATH
+ENV PATH=/app/.venv/bin:/root/.local/bin:$PATH
+
+# Sync dependencies inside the final image using uv
+# And ensure pip is available for runtime installs
+RUN uv sync --frozen --no-dev --extra api --no-editable \
+    && /app/.venv/bin/python -m ensurepip --upgrade
+
+# Create persistent data directories
+RUN mkdir -p /app/data/rag_storage /app/data/inputs /app/data/tiktoken
+
+# Copy cached tokenizer assets prepared in the builder stage
+COPY --from=builder /app/data/tiktoken /app/data/tiktoken
+
+# Docker data directories
+ENV TIKTOKEN_CACHE_DIR=/app/data/tiktoken
+ENV WORKING_DIR=/app/data/rag_storage
+ENV INPUT_DIR=/app/data/inputs
+
+# Expose API port
+EXPOSE 9621
+
+# Set entrypoint
+ENTRYPOINT ["python", "-m", "lightrag.api.lightrag_server"]