feat(training): add Media Pipeline — TTS Audio, Presentation Video, Bulk Generation

Phase A: 8 new IT-Security training modules (SEC-PWD, SEC-DESK, SEC-KIAI,
SEC-BYOD, SEC-VIDEO, SEC-USB, SEC-INC, SEC-HOME) with CTM entries.
Bulk content and quiz generation endpoints for all 28 modules.

Phase B: Piper TTS service (Python/FastAPI) for local German speech synthesis.
training_media table, TTSClient in Go backend, audio generation endpoints,
AudioPlayer component in frontend. MinIO storage integration.

Phase C: FFmpeg presentation video pipeline — LLM generates slide scripts,
ImageMagick renders 1920x1080 slides, FFmpeg combines with audio to MP4.
VideoPlayer and ScriptPreview components in frontend.

New files: 15 created, 9 modified
- compliance-tts-service/ (Dockerfile, main.py, tts_engine.py, storage.py,
  slide_renderer.py, video_generator.py)
- migrations 014-016 (training engine, IT-security modules, media table)
- training package (models, store, content_generator, media, handlers)
- frontend (AudioPlayer, VideoPlayer, ScriptPreview, api, types, page)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

compliance-tts-service/Dockerfile

@@ -0,0 +1,44 @@
+FROM python:3.12-slim
+
+# System dependencies
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    ffmpeg \
+    libsndfile1 \
+    imagemagick \
+    fonts-dejavu-core \
+    wget \
+    && rm -rf /var/lib/apt/lists/*
+
+# Create non-root user
+RUN useradd -m -u 1000 ttsuser
+
+WORKDIR /app
+
+# Python dependencies
+COPY requirements.txt .
+RUN pip install --no-cache-dir -r requirements.txt
+
+# Download Piper model (German, thorsten, high quality)
+RUN mkdir -p /app/models && \
+    wget -q -O /app/models/de_DE-thorsten-high.onnx \
+    "https://huggingface.co/rhasspy/piper-voices/resolve/main/de/de_DE/thorsten/high/de_DE-thorsten-high.onnx" && \
+    wget -q -O /app/models/de_DE-thorsten-high.onnx.json \
+    "https://huggingface.co/rhasspy/piper-voices/resolve/main/de/de_DE/thorsten/high/de_DE-thorsten-high.onnx.json"
+
+# Copy application
+COPY . .
+
+# Fix ImageMagick policy for PDF/text rendering
+RUN if [ -f /etc/ImageMagick-6/policy.xml ]; then \
+    sed -i 's/rights="none" pattern="PDF"/rights="read|write" pattern="PDF"/' /etc/ImageMagick-6/policy.xml; \
+    fi
+
+RUN chown -R ttsuser:ttsuser /app
+USER ttsuser
+
+EXPOSE 8095
+
+HEALTHCHECK --interval=30s --timeout=10s --start-period=60s --retries=3 \
+    CMD python -c "import urllib.request; urllib.request.urlopen('http://127.0.0.1:8095/health')"
+
+CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "8095"]