feat(training+controls): interactive video pipeline, training blocks, control generator, CE libraries

Interactive Training Videos (CP-TRAIN):
- DB migration 022: training_checkpoints + checkpoint_progress tables
- NarratorScript generation via Anthropic (AI Teacher persona, German)
- TTS batch synthesis + interactive video pipeline (slides + checkpoint slides + FFmpeg)
- 4 new API endpoints: generate-interactive, interactive-manifest, checkpoint submit, checkpoint progress
- InteractiveVideoPlayer component (HTML5 Video, quiz overlay, seek protection, progress tracking)
- Learner portal integration with automatic completion on all checkpoints passed
- 30 new tests (handler validation + grading logic + manifest/progress + seek protection)

Training Blocks:
- Block generator, block store, block config CRUD + preview/generate endpoints
- Migration 021: training_blocks schema

Control Generator + Canonical Library:
- Control generator routes + service enhancements
- Canonical control library helpers, sidebar entry
- Citation backfill service + tests
- CE libraries data (hazard, protection, evidence, lifecycle, components)

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

compliance-tts-service/video_generator.py

@@ -115,6 +115,139 @@ def generate_presentation_video(
     return output_path, video_duration
 
 
+def generate_interactive_presentation_video(
+    script: dict,
+    audio_sections: list[dict],
+    output_dir: str,
+    storage,
+    audio_bucket: str,
+) -> tuple[str, float]:
+    """
+    Generate an interactive presentation video from narrator script + per-section audio.
+
+    Includes checkpoint slides (red-bordered pause markers) between sections.
+    Returns (mp4_path, duration_seconds).
+    """
+    from slide_renderer import render_slide, render_title_slide, render_checkpoint_slide
+
+    title = script.get("title", "Compliance Training")
+    sections = script.get("sections", [])
+
+    if not sections:
+        raise ValueError("Script has no sections")
+    if not audio_sections:
+        raise ValueError("No audio sections provided")
+
+    # Step 1: Download all section audio files
+    audio_paths = []
+    for i, sec in enumerate(audio_sections):
+        obj_key = sec.get("audio_object_key", "")
+        if not obj_key:
+            continue
+        audio_path = os.path.join(output_dir, f"section_{i}.mp3")
+        storage.client.download_file(audio_bucket, obj_key, audio_path)
+        audio_paths.append((i, audio_path, sec.get("duration", 0.0)))
+
+    # Step 2: Render slides
+    slides_dir = os.path.join(output_dir, "slides")
+    os.makedirs(slides_dir, exist_ok=True)
+
+    # All slide entries: (png_path, duration)
+    slide_entries = []
+
+    # Title slide (5 seconds)
+    title_path = os.path.join(slides_dir, "slide_000_title.png")
+    render_title_slide(title, "Interaktive Compliance-Schulung", title_path)
+    slide_entries.append((title_path, 5.0))
+
+    total_content_slides = sum(1 for _ in sections)  # for numbering
+    slide_num = 1
+
+    for i, section in enumerate(sections):
+        heading = section.get("heading", "")
+        narrator_text = section.get("narrator_text", "")
+        bullet_points = section.get("bullet_points", [])
+
+        # Content slide for this section
+        slide_path = os.path.join(slides_dir, f"slide_{i+1:03d}_content.png")
+        render_slide(
+            heading=heading,
+            text=narrator_text[:200] if len(narrator_text) > 200 else narrator_text,
+            bullet_points=bullet_points,
+            slide_number=slide_num + 1,
+            total_slides=total_content_slides + 1,
+            module_code=script.get("module_code", ""),
+            output_path=slide_path,
+        )
+        slide_num += 1
+
+        # Duration = matching audio section duration
+        section_duration = 5.0  # fallback
+        if i < len(audio_paths):
+            section_duration = audio_paths[i][2] or 5.0
+        slide_entries.append((slide_path, section_duration))
+
+        # Checkpoint slide (if this section has a checkpoint)
+        checkpoint = section.get("checkpoint")
+        if checkpoint:
+            cp_title = checkpoint.get("title", f"Checkpoint {i+1}")
+            questions = checkpoint.get("questions", [])
+            question_preview = questions[0].get("question", "") if questions else ""
+            cp_path = os.path.join(slides_dir, f"slide_{i+1:03d}_checkpoint.png")
+            render_checkpoint_slide(cp_title, question_preview, len(questions), cp_path)
+            slide_entries.append((cp_path, 3.0))  # 3s still frame as pause marker
+
+    # Step 3: Concatenate all section audio files into one
+    combined_audio = os.path.join(output_dir, "combined_audio.mp3")
+    if len(audio_paths) == 1:
+        import shutil
+        shutil.copy2(audio_paths[0][1], combined_audio)
+    elif len(audio_paths) > 1:
+        # Use FFmpeg to concatenate audio
+        audio_list_path = os.path.join(output_dir, "audio_list.txt")
+        with open(audio_list_path, "w") as f:
+            for _, apath, _ in audio_paths:
+                f.write(f"file '{apath}'\n")
+        cmd = [
+            "ffmpeg", "-y", "-f", "concat", "-safe", "0",
+            "-i", audio_list_path, "-c", "copy", combined_audio,
+        ]
+        result = subprocess.run(cmd, capture_output=True, text=True, timeout=300)
+        if result.returncode != 0:
+            raise RuntimeError(f"FFmpeg audio concat failed: {result.stderr}")
+    else:
+        raise ValueError("No audio files to concatenate")
+
+    # Step 4: Create FFmpeg concat file for slides
+    concat_path = os.path.join(output_dir, "concat.txt")
+    with open(concat_path, "w") as f:
+        for slide_path, dur in slide_entries:
+            f.write(f"file '{slide_path}'\n")
+            f.write(f"duration {dur:.2f}\n")
+        # Repeat last slide for FFmpeg concat demuxer
+        f.write(f"file '{slide_entries[-1][0]}'\n")
+
+    # Step 5: Combine slides + audio into MP4
+    output_path = os.path.join(output_dir, "interactive.mp4")
+    cmd = [
+        "ffmpeg", "-y",
+        "-f", "concat", "-safe", "0", "-i", concat_path,
+        "-i", combined_audio,
+        "-c:v", "libx264", "-pix_fmt", "yuv420p",
+        "-c:a", "aac", "-b:a", "128k",
+        "-shortest",
+        "-movflags", "+faststart",
+        output_path,
+    ]
+
+    result = subprocess.run(cmd, capture_output=True, text=True, timeout=600)
+    if result.returncode != 0:
+        raise RuntimeError(f"FFmpeg interactive video failed: {result.stderr}")
+
+    video_duration = _get_duration(output_path)
+    return output_path, video_duration
+
+
 def _get_duration(file_path: str) -> float:
     """Get media duration using FFprobe."""
     cmd = [