Phase 15.5 구현: 화자 구분 (Speaker Diarization)

- Sidecar: pyannote /diarize 엔드포인트 + requirements.txt 업데이트
- LLM 기반 화자 추정 (Phase 1 — 오디오 보존 없이 전사 텍스트 분석)
- CaptionSegment에 speaker 필드 추가
- EditableSegment: 화자별 색상 바 + 화자 Chip 표시
- TranscriptTab: 화자 구분 버튼 + 진행률
- 설정: HuggingFace 토큰 입력 + Diarization 토글
- IPC: DIARIZE + DIARIZATION_PROGRESS 채널
- 에러코드: 895-897
- 12개 locale i18n

src/renderer/components/SettingsModal.tsx

@@ -642,6 +642,46 @@ export function SettingsModal({ open, onClose }: SettingsModalProps): React.Reac
                   <MenuItem value="zh">{t('settings.sttLang.zh')}</MenuItem>
                 </Select>
               </FormControl>
+
+              <Divider sx={{ borderColor: d3roPalette.border.subtle }} />
+
+              <Typography variant="overline" sx={{ color: d3roPalette.text.label, letterSpacing: '1.5px' }}>
+                {t('settings.diarization')}
+              </Typography>
+
+              <TextField
+                label={t('settings.hfToken')}
+                type="password"
+                value={(config as Record<string, unknown>)['hfToken'] as string ?? ''}
+                onChange={(e) => updateConfig('hfToken' as keyof AppConfig, e.target.value as never)}
+                fullWidth
+                size="small"
+                helperText={t('settings.hfTokenHint')}
+              />
+
+              <FormControlLabel
+                control={
+                  <Switch
+                    checked={(config as Record<string, unknown>)['diarizationEnabled'] as boolean ?? false}
+                    onChange={(e) => updateConfig('diarizationEnabled' as keyof AppConfig, e.target.checked as never)}
+                    size="small"
+                    sx={{
+                      '& .MuiSwitch-switchBase.Mui-checked': { color: d3roPalette.tag.purple },
+                      '& .MuiSwitch-switchBase.Mui-checked + .MuiSwitch-track': {
+                        backgroundColor: d3roPalette.tag.purple,
+                      },
+                    }}
+                  />
+                }
+                label={
+                  <Box>
+                    <Typography variant="body2" sx={{ fontSize: '12px' }}>{t('settings.diarization')}</Typography>
+                    <Typography variant="caption" sx={{ color: d3roPalette.text.inactive, fontSize: '11px' }}>
+                      {t('settings.diarizationHint')}
+                    </Typography>
+                  </Box>
+                }
+              />
             </Box>
           </TabPanel>