feat: wire GraphRAG API handlers, activities, and database layer

action/canvas_compatibility.go

@@ -293,3 +293,62 @@ func knowledgeBaseData() string {
 	// For now, return empty - real implementation loads from file
 	return ""
 }
+
+// CanvasCompatibilityInput for Temporal activity
+type CanvasCompatibilityInput struct {
+	Nodes []db.WorkflowNode `json:"nodes"`
+	Edges []db.WorkflowEdge `json:"edges"`
+}
+
+// CanvasCompatibilityOutput returns validation results
+type CanvasCompatibilityOutput struct {
+	IsValid           bool                      `json:"is_valid"`
+	Incompatibilities []IncompatibilityWarning  `json:"incompatibilities"`
+	DisconnectedNodes []string                  `json:"disconnected_nodes"`
+	Warnings          []string                  `json:"warnings"`
+}
+
+// CanvasCompatibilityActivity validates workflow canvas for type mismatches and isolation
+func CanvasCompatibilityActivity(ctx interface{}, input CanvasCompatibilityInput) (CanvasCompatibilityOutput, error) {
+	output := CanvasCompatibilityOutput{
+		IsValid:           true,
+		Incompatibilities: []IncompatibilityWarning{},
+		DisconnectedNodes: []string{},
+		Warnings:          []string{},
+	}
+
+	// Check all edges for compatibility
+	for _, edge := range input.Edges {
+		var sourceNode, targetNode *db.WorkflowNode
+		for i := range input.Nodes {
+			if input.Nodes[i].ID == edge.Source {
+				sourceNode = &input.Nodes[i]
+			}
+			if input.Nodes[i].ID == edge.Target {
+				targetNode = &input.Nodes[i]
+			}
+		}
+
+		if sourceNode != nil && targetNode != nil {
+			if warning, err := ValidateConnection(sourceNode, targetNode); err != nil {
+				output.IsValid = false
+				output.Incompatibilities = append(output.Incompatibilities, warning)
+			}
+		}
+	}
+
+	// Find disconnected nodes
+	connected := make(map[string]bool)
+	for _, edge := range input.Edges {
+		connected[edge.Source] = true
+		connected[edge.Target] = true
+	}
+
+	for _, node := range input.Nodes {
+		if node.Type == "activity" && !connected[node.ID] {
+			output.DisconnectedNodes = append(output.DisconnectedNodes, node.ID)
+		}
+	}
+
+	return output, nil
+}