Fix missing metadata.source_kind in exported JSON (#15)

[p0dalirius]

Linked Issue

Closes #15

Root Cause

The graph is built with NewOpenGraph("KeyCredentialBase"), which records the source kind, but it was serialized via og.ExportJSON(false). The boolean argument is includeMetadata; when false, OpenGraph.ExportJSON skips writing the top-level metadata object entirely. As a result every artifact was produced without the metadata.source_kind block that BloodHound uses to scope ingests.

Fix Description

Call og.ExportJSON(true) so the serializer emits the metadata sibling of graph with "source_kind": "KeyCredentialBase". This is the minimal change that restores the documented output shape; the rest of the export path is unchanged.

How Verified

Static: with includeMetadata == true, the guarded block at gopengraph/OpenGraph.go:577 writes graphData["metadata"] = {"source_kind": g.sourceKind}, and g.sourceKind is "KeyCredentialBase" from NewOpenGraph. go build ./... and go vet ./... pass.

Test Coverage

None: exercising the full export requires a live LDAP/AD target to populate the graph; the changed line is a one-argument flag whose downstream behavior is covered by gopengraph's own export tests.

Scope of Change

• Files changed: main.go
• Submodule pointer updated: no
• Behavioral changes outside the bug fix: none