chore(graphify): add knowledge graph output for codebase exploration

Includes interactive graph visualization (graph.html), audit report
(GRAPH_REPORT.md), raw graph data (graph.json), and extraction
caches built from 349 source files (2741 nodes, 4999 edges).

graphify-out/cost.json

@@ -0,0 +1,12 @@
+{
+  "runs": [
+    {
+      "date": "2026-07-04T03:02:52.409955+00:00",
+      "input_tokens": 0,
+      "output_tokens": 0,
+      "files": 349
+    }
+  ],
+  "total_input_tokens": 0,
+  "total_output_tokens": 0
+}