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>

ai-compliance-sdk/internal/training/media.go

@@ -0,0 +1,186 @@
+package training
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"time"
+
+	"github.com/google/uuid"
+)
+
+// MediaType represents audio or video
+type MediaType string
+
+const (
+	MediaTypeAudio MediaType = "audio"
+	MediaTypeVideo MediaType = "video"
+)
+
+// MediaStatus represents the processing status
+type MediaStatus string
+
+const (
+	MediaStatusProcessing MediaStatus = "processing"
+	MediaStatusCompleted  MediaStatus = "completed"
+	MediaStatusFailed     MediaStatus = "failed"
+)
+
+// TrainingMedia represents a generated media file
+type TrainingMedia struct {
+	ID              uuid.UUID       `json:"id"`
+	ModuleID        uuid.UUID       `json:"module_id"`
+	ContentID       *uuid.UUID      `json:"content_id,omitempty"`
+	MediaType       MediaType       `json:"media_type"`
+	Status          MediaStatus     `json:"status"`
+	Bucket          string          `json:"bucket"`
+	ObjectKey       string          `json:"object_key"`
+	FileSizeBytes   int64           `json:"file_size_bytes"`
+	DurationSeconds float64         `json:"duration_seconds"`
+	MimeType        string          `json:"mime_type"`
+	VoiceModel      string          `json:"voice_model"`
+	Language        string          `json:"language"`
+	Metadata        json.RawMessage `json:"metadata"`
+	ErrorMessage    string          `json:"error_message,omitempty"`
+	GeneratedBy     string          `json:"generated_by"`
+	IsPublished     bool            `json:"is_published"`
+	CreatedAt       time.Time       `json:"created_at"`
+	UpdatedAt       time.Time       `json:"updated_at"`
+}
+
+// ============================================================================
+// TTS Client
+// ============================================================================
+
+// TTSClient communicates with the compliance-tts-service
+type TTSClient struct {
+	baseURL    string
+	httpClient *http.Client
+}
+
+// NewTTSClient creates a new TTS service client
+func NewTTSClient(baseURL string) *TTSClient {
+	return &TTSClient{
+		baseURL: baseURL,
+		httpClient: &http.Client{
+			Timeout: 5 * time.Minute,
+		},
+	}
+}
+
+// TTSSynthesizeRequest is the request to synthesize audio
+type TTSSynthesizeRequest struct {
+	Text      string `json:"text"`
+	Language  string `json:"language"`
+	Voice     string `json:"voice"`
+	ModuleID  string `json:"module_id"`
+	ContentID string `json:"content_id,omitempty"`
+}
+
+// TTSSynthesizeResponse is the response from audio synthesis
+type TTSSynthesizeResponse struct {
+	AudioID         string  `json:"audio_id"`
+	Bucket          string  `json:"bucket"`
+	ObjectKey       string  `json:"object_key"`
+	DurationSeconds float64 `json:"duration_seconds"`
+	SizeBytes       int64   `json:"size_bytes"`
+}
+
+// TTSGenerateVideoRequest is the request to generate a video
+type TTSGenerateVideoRequest struct {
+	Script        map[string]interface{} `json:"script"`
+	AudioObjectKey string                `json:"audio_object_key"`
+	ModuleID       string                `json:"module_id"`
+}
+
+// TTSGenerateVideoResponse is the response from video generation
+type TTSGenerateVideoResponse struct {
+	VideoID         string  `json:"video_id"`
+	Bucket          string  `json:"bucket"`
+	ObjectKey       string  `json:"object_key"`
+	DurationSeconds float64 `json:"duration_seconds"`
+	SizeBytes       int64   `json:"size_bytes"`
+}
+
+// Synthesize calls the TTS service to create audio
+func (c *TTSClient) Synthesize(ctx context.Context, req *TTSSynthesizeRequest) (*TTSSynthesizeResponse, error) {
+	body, err := json.Marshal(req)
+	if err != nil {
+		return nil, fmt.Errorf("marshal request: %w", err)
+	}
+
+	httpReq, err := http.NewRequestWithContext(ctx, "POST", c.baseURL+"/synthesize", bytes.NewReader(body))
+	if err != nil {
+		return nil, fmt.Errorf("create request: %w", err)
+	}
+	httpReq.Header.Set("Content-Type", "application/json")
+
+	resp, err := c.httpClient.Do(httpReq)
+	if err != nil {
+		return nil, fmt.Errorf("TTS service request failed: %w", err)
+	}
+	defer resp.Body.Close()
+
+	respBody, _ := io.ReadAll(resp.Body)
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("TTS service error (%d): %s", resp.StatusCode, string(respBody))
+	}
+
+	var result TTSSynthesizeResponse
+	if err := json.Unmarshal(respBody, &result); err != nil {
+		return nil, fmt.Errorf("parse TTS response: %w", err)
+	}
+
+	return &result, nil
+}
+
+// GenerateVideo calls the TTS service to create a presentation video
+func (c *TTSClient) GenerateVideo(ctx context.Context, req *TTSGenerateVideoRequest) (*TTSGenerateVideoResponse, error) {
+	body, err := json.Marshal(req)
+	if err != nil {
+		return nil, fmt.Errorf("marshal request: %w", err)
+	}
+
+	httpReq, err := http.NewRequestWithContext(ctx, "POST", c.baseURL+"/generate-video", bytes.NewReader(body))
+	if err != nil {
+		return nil, fmt.Errorf("create request: %w", err)
+	}
+	httpReq.Header.Set("Content-Type", "application/json")
+
+	resp, err := c.httpClient.Do(httpReq)
+	if err != nil {
+		return nil, fmt.Errorf("TTS service request failed: %w", err)
+	}
+	defer resp.Body.Close()
+
+	respBody, _ := io.ReadAll(resp.Body)
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("TTS service error (%d): %s", resp.StatusCode, string(respBody))
+	}
+
+	var result TTSGenerateVideoResponse
+	if err := json.Unmarshal(respBody, &result); err != nil {
+		return nil, fmt.Errorf("parse TTS response: %w", err)
+	}
+
+	return &result, nil
+}
+
+// IsHealthy checks if the TTS service is responsive
+func (c *TTSClient) IsHealthy(ctx context.Context) bool {
+	httpReq, err := http.NewRequestWithContext(ctx, "GET", c.baseURL+"/health", nil)
+	if err != nil {
+		return false
+	}
+
+	resp, err := c.httpClient.Do(httpReq)
+	if err != nil {
+		return false
+	}
+	defer resp.Body.Close()
+
+	return resp.StatusCode == http.StatusOK
+}