feat: independent TKG processing mechanism with operation logging

- Created src/core/tkg/ module with service, log, and models
- Added tkg_operation_log table for tracking all TKG operations
- TkgService: build, rebuild (with force option), delete, get_operations
- Updated rebuild endpoint with force parameter
- Added GET /api/v1/file/:file_uuid/tkg for operation history
- Added DELETE /api/v1/file/:file_uuid/tkg for TKG deletion
- TKG rebuild now always triggers Rule 2 (even with 0 edges)
- Full audit trail for all TKG operations (create/update/delete/rebuild)

src/core/tkg/models.rs

@@ -0,0 +1,94 @@
+use serde::{Deserialize, Serialize};
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct TkgOperationLog {
+    pub id: i64,
+    pub file_uuid: String,
+    pub operation: String,
+    pub node_type: Option<String>,
+    pub edge_type: Option<String>,
+    pub nodes_created: i32,
+    pub nodes_updated: i32,
+    pub nodes_deleted: i32,
+    pub edges_created: i32,
+    pub edges_updated: i32,
+    pub edges_deleted: i32,
+    pub status: String,
+    pub error_message: Option<String>,
+    pub started_at: String,
+    pub completed_at: Option<String>,
+    pub properties: Option<serde_json::Value>,
+}
+
+#[derive(Debug, Clone, Default)]
+pub struct TkgNodeStats {
+    pub created: i32,
+    pub updated: i32,
+    pub deleted: i32,
+}
+
+#[derive(Debug, Clone, Default)]
+pub struct TkgEdgeStats {
+    pub created: i32,
+    pub updated: i32,
+    pub deleted: i32,
+}
+
+#[derive(Debug, Clone, Default)]
+pub struct TkgBuildStats {
+    pub face_track_nodes: i32,
+    pub gaze_track_nodes: i32,
+    pub lip_track_nodes: i32,
+    pub text_region_nodes: i32,
+    pub appearance_trace_nodes: i32,
+    pub accessory_nodes: i32,
+    pub object_nodes: i32,
+    pub hand_nodes: i32,
+    pub speaker_nodes: i32,
+    pub co_occurrence_edges: i32,
+    pub speaker_face_edges: i32,
+    pub face_face_edges: i32,
+    pub mutual_gaze_edges: i32,
+    pub lip_sync_edges: i32,
+    pub has_appearance_edges: i32,
+    pub wears_edges: i32,
+    pub hand_object_edges: i32,
+}
+
+impl TkgBuildStats {
+    pub fn total_nodes(&self) -> i32 {
+        self.face_track_nodes + self.gaze_track_nodes + self.lip_track_nodes
+            + self.text_region_nodes + self.appearance_trace_nodes + self.accessory_nodes
+            + self.object_nodes + self.hand_nodes + self.speaker_nodes
+    }
+
+    pub fn total_edges(&self) -> i32 {
+        self.co_occurrence_edges + self.speaker_face_edges + self.face_face_edges
+            + self.mutual_gaze_edges + self.lip_sync_edges + self.has_appearance_edges
+            + self.wears_edges + self.hand_object_edges
+    }
+
+    pub fn to_json(&self) -> serde_json::Value {
+        serde_json::json!({
+            "face_track_nodes": self.face_track_nodes,
+            "gaze_track_nodes": self.gaze_track_nodes,
+            "lip_track_nodes": self.lip_track_nodes,
+            "text_region_nodes": self.text_region_nodes,
+            "appearance_trace_nodes": self.appearance_trace_nodes,
+            "accessory_nodes": self.accessory_nodes,
+            "object_nodes": self.object_nodes,
+            "hand_nodes": self.hand_nodes,
+            "speaker_nodes": self.speaker_nodes,
+            "co_occurrence_edges": self.co_occurrence_edges,
+            "speaker_face_edges": self.speaker_face_edges,
+            "face_face_edges": self.face_face_edges,
+            "mutual_gaze_edges": self.mutual_gaze_edges,
+            "lip_sync_edges": self.lip_sync_edges,
+            "has_appearance_edges": self.has_appearance_edges,
+            "wears_edges": self.wears_edges,
+            "hand_object_edges": self.hand_object_edges,
+            "total_nodes": self.total_nodes(),
+            "total_edges": self.total_edges(),
+        })
+    }
+}