Implemented a module to detect backchannel segments, and updated the coalesce module to ignore them when coalescing same-speaker turns

internal/model/model.go

@@ -56,6 +56,7 @@ type Segment struct {
 	Start              float64  `json:"start"`
 	End                float64  `json:"end"`
 	Text               string   `json:"text"`
+	Categories         []string `json:"categories,omitempty"`
 	Words              []Word   `json:"words,omitempty"`
 	OverlapGroupID     int      `json:"overlap_group_id,omitempty"`
 }