fix: parse nanoflow activities, flows, and return type from BSON

The nanoflow parser was only reading Name, Documentation, and Parameters,
skipping ObjectCollection (activities), Flows (sequence/annotation flows),
and MicroflowReturnType. This caused DESCRIBE NANOFLOW to always show an
empty body and catalog.nanoflows to report 0 activities.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: ako

sdk/mpr/parser_nanoflow.go

@@ -40,12 +40,68 @@ func (r *Reader) parseNanoflow(unitID, containerID string, contents []byte) (*mi
 		nf.Excluded = excluded
 	}
 
-	// Parse parameters
-	if params, ok := raw["Parameters"].([]any); ok {
-		for _, p := range params {
-			if paramMap, ok := p.(map[string]any); ok {
-				param := parseMicroflowParameter(paramMap)
-				nf.Parameters = append(nf.Parameters, param)
+	// Parse parameters (same format variants as microflows)
+	var paramsArray any
+	if mpc, ok := raw["MicroflowParameterCollection"]; ok {
+		if mpcMap := extractBsonMap(mpc); mpcMap != nil {
+			paramsArray = mpcMap["Parameters"]
+		}
+	} else {
+		paramKey := "MicroflowParameters"
+		if _, ok := raw[paramKey]; !ok {
+			paramKey = "Parameters"
+		}
+		paramsArray = raw[paramKey]
+	}
+	for _, p := range extractBsonSlice(paramsArray) {
+		if paramMap := extractBsonMap(p); paramMap != nil {
+			param := parseMicroflowParameter(paramMap)
+			nf.Parameters = append(nf.Parameters, param)
+		}
+	}
+
+	// Parse return type (uses same BSON key as microflows)
+	if rt, ok := raw["MicroflowReturnType"].(map[string]any); ok {
+		nf.ReturnType = parseMicroflowDataType(rt)
+	}
+
+	// Parse object collection (activities)
+	if oc := extractBsonMap(raw["ObjectCollection"]); oc != nil {
+		nf.ObjectCollection = parseMicroflowObjectCollection(oc)
+	}
+
+	// Also extract parameters from ObjectCollection.Objects (modern format)
+	if len(nf.Parameters) == 0 {
+		if ocRaw := extractBsonMap(raw["ObjectCollection"]); ocRaw != nil {
+			for _, obj := range extractBsonSlice(ocRaw["Objects"]) {
+				if objMap := extractBsonMap(obj); objMap != nil {
+					if typeName, _ := objMap["$Type"].(string); typeName == "Microflows$MicroflowParameter" {
+						param := parseMicroflowParameter(objMap)
+						nf.Parameters = append(nf.Parameters, param)
+					}
+				}
+			}
+		}
+	}
+
+	// Parse Flows array (SequenceFlows and AnnotationFlows at root level)
+	if flowsRaw := raw["Flows"]; flowsRaw != nil {
+		if nf.ObjectCollection == nil {
+			nf.ObjectCollection = &microflows.MicroflowObjectCollection{}
+		}
+		for _, f := range extractBsonSlice(flowsRaw) {
+			if flowMap := extractBsonMap(f); flowMap != nil {
+				typeName, _ := flowMap["$Type"].(string)
+				switch typeName {
+				case "Microflows$AnnotationFlow":
+					if af := parseAnnotationFlow(flowMap); af != nil {
+						nf.ObjectCollection.AnnotationFlows = append(nf.ObjectCollection.AnnotationFlows, af)
+					}
+				default:
+					if flow := parseSequenceFlow(flowMap); flow != nil {
+						nf.ObjectCollection.Flows = append(nf.ObjectCollection.Flows, flow)
+					}
+				}
 			}
 		}
 	}