Refactor downloader and file manager for improved rclone integration and add healthcheck and smoke test options

- Renamed download flags in ContentDownloader for clarity.
- Enhanced FileManager with methods to build upload paths and verify existing files for rclone uploads.
- Updated StreamProcessor to return success status for stream processing.
- Added rclone smoke test and healthcheck functions to validate configuration and tool availability.
- Improved environment variable handling with a utility function.
- Updated TwitchArchive to incorporate new rclone verification and processing logic.
- Added unit tests for new functionality and refactored existing tests for clarity and coverage.

Co-authored-by: Copilot <copilot@github.com>

docker/entrypoint.sh

@@ -0,0 +1,6 @@
+#!/bin/sh
+set -eu
+
+mkdir -p /app/archive /app/config /app/bin/temp
+
+exec "$@"

docker/python.Dockerfile

@@ -0,0 +1,49 @@
+FROM python:3.12-slim
+
+ARG TWITCH_DOWNLOADER_VERSION=1.56.4
+ARG TARGETARCH
+
+ENV PYTHONUNBUFFERED=1 \
+    PIP_NO_CACHE_DIR=1 \
+    RCLONE_CONFIG=/app/config/rclone.conf
+
+WORKDIR /app
+
+RUN apt-get update \
+    && apt-get install -y --no-install-recommends \
+        ca-certificates \
+        curl \
+        ffmpeg \
+        libicu-dev \
+        rclone \
+        unzip \
+    && rm -rf /var/lib/apt/lists/*
+
+RUN set -eux; \
+    case "${TARGETARCH}" in \
+        amd64) twitch_downloader_arch='Linux-x64' ;; \
+        arm64) twitch_downloader_arch='LinuxArm64' ;; \
+        arm) twitch_downloader_arch='LinuxArm' ;; \
+        *) echo "Unsupported TARGETARCH: ${TARGETARCH}" >&2; exit 1 ;; \
+    esac; \
+    curl -fsSL -o /tmp/TwitchDownloaderCLI.zip "https://github.com/lay295/TwitchDownloader/releases/download/${TWITCH_DOWNLOADER_VERSION}/TwitchDownloaderCLI-${TWITCH_DOWNLOADER_VERSION}-${twitch_downloader_arch}.zip"; \
+    mkdir -p /tmp/twitchdownloader; \
+    unzip -j /tmp/TwitchDownloaderCLI.zip TwitchDownloaderCLI -d /tmp/twitchdownloader; \
+    install -m 0755 /tmp/twitchdownloader/TwitchDownloaderCLI /usr/local/bin/TwitchDownloaderCLI; \
+    rm -rf /tmp/TwitchDownloaderCLI.zip /tmp/twitchdownloader
+
+COPY requirements.txt ./requirements.txt
+
+RUN python -m pip install --upgrade pip \
+    && python -m pip install -r requirements.txt
+
+COPY . /app
+
+RUN mkdir -p /app/archive /app/config /app/bin/temp
+
+COPY docker/entrypoint.sh /usr/local/bin/twitch-archive-entrypoint
+
+RUN chmod +x /usr/local/bin/twitch-archive-entrypoint
+
+ENTRYPOINT ["twitch-archive-entrypoint"]
+CMD ["python", "twitch-archive.py", "-u", "vinesauce"]