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/slide_renderer.py

@@ -130,3 +130,97 @@ def render_title_slide(
     result = subprocess.run(cmd, capture_output=True, text=True, timeout=30)
     if result.returncode != 0:
         raise RuntimeError(f"ImageMagick title slide failed: {result.stderr}")
+
+
+def render_checkpoint_slide(
+    title: str,
+    question_preview: str,
+    question_count: int,
+    output_path: str,
+) -> None:
+    """Render a checkpoint slide with red border and quiz preview."""
+    border_width = 12
+    cmd = [
+        "convert",
+        "-size", f"{WIDTH}x{HEIGHT}",
+        "xc:white",
+        # Red border (full rectangle, then white inner)
+        "-fill", "#c0392b",
+        "-draw", f"rectangle 0,0 {WIDTH},{HEIGHT}",
+        "-fill", "white",
+        "-draw", f"rectangle {border_width},{border_width} {WIDTH - border_width},{HEIGHT - border_width}",
+        # Red header bar
+        "-fill", "#c0392b",
+        "-draw", f"rectangle {border_width},{border_width} {WIDTH - border_width},{HEADER_HEIGHT + border_width}",
+        # CHECKPOINT label
+        "-fill", "white",
+        "-font", FONT_BOLD,
+        "-pointsize", "48",
+        "-gravity", "NorthWest",
+        "-annotate", f"+{60 + border_width}+{(HEADER_HEIGHT - 48) // 2 + border_width}",
+        f"CHECKPOINT: {title[:50]}",
+    ]
+
+    y_pos = HEADER_HEIGHT + border_width + 60
+
+    # Instruction text
+    cmd.extend([
+        "-fill", "#333333",
+        "-font", FONT,
+        "-pointsize", "32",
+        "-gravity", "NorthWest",
+        "-annotate", f"+80+{y_pos}",
+        "Bitte beantworten Sie die folgenden Fragen,",
+    ])
+    y_pos += 44
+
+    cmd.extend([
+        "-fill", "#333333",
+        "-font", FONT,
+        "-pointsize", "32",
+        "-gravity", "NorthWest",
+        "-annotate", f"+80+{y_pos}",
+        "um mit der Schulung fortzufahren.",
+    ])
+    y_pos += 80
+
+    # Question preview
+    if question_preview:
+        preview = textwrap.fill(question_preview, width=70)
+        cmd.extend([
+            "-fill", "#666666",
+            "-font", FONT,
+            "-pointsize", "26",
+            "-gravity", "NorthWest",
+            "-annotate", f"+80+{y_pos}",
+            f"Erste Frage: {preview[:120]}...",
+        ])
+        y_pos += 50
+
+    # Question count
+    cmd.extend([
+        "-fill", "#888888",
+        "-font", FONT,
+        "-pointsize", "24",
+        "-gravity", "NorthWest",
+        "-annotate", f"+80+{y_pos}",
+        f"{question_count} Fragen in diesem Checkpoint",
+    ])
+
+    # Footer
+    cmd.extend([
+        "-fill", "#f0f0f0",
+        "-draw", f"rectangle {border_width},{HEIGHT - FOOTER_HEIGHT - border_width} {WIDTH - border_width},{HEIGHT - border_width}",
+        "-fill", "#c0392b",
+        "-font", FONT_BOLD,
+        "-pointsize", "22",
+        "-gravity", "South",
+        "-annotate", f"+0+{(FOOTER_HEIGHT - 22) // 2 + border_width}",
+        "Video wird pausiert — Quiz im Player beantworten",
+    ])
+
+    cmd.append(output_path)
+
+    result = subprocess.run(cmd, capture_output=True, text=True, timeout=30)
+    if result.returncode != 0:
+        raise RuntimeError(f"ImageMagick checkpoint slide failed: {result.stderr}")