fix: batched DETACH DELETE to avoid Neo4j memory pool limit on large graphs

MATCH (n) DETACH DELETE n in a single transaction tries to delete 140K nodes
+ 130K edges at once, exceeding the memory pool. Now deletes in batches of
5000 nodes per transaction.

Applied to both EnrichCommand and GraphStore.bulkSave().

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

Author: aksOps

src/main/java/io/github/randomcodespace/iq/cli/EnrichCommand.java

@@ -168,11 +168,17 @@ private int enrichFromCache(AnalysisCache cache, Path root, NumberFormat nf, Ins
             dbms = new DatabaseManagementServiceBuilder(graphPath).build();
             GraphDatabaseService db = dbms.database("neo4j");
 
-            // Clear existing data
-            try (Transaction tx = db.beginTx()) {
-                tx.execute("MATCH (n) DETACH DELETE n");
-                tx.commit();
-            }
+            // Clear existing data in batches to avoid memory pool limit on large graphs
+            CliOutput.info("  Clearing existing graph...");
+            int deleted;
+            do {
+                try (Transaction tx = db.beginTx()) {
+                    var result = tx.execute(
+                            "MATCH (n) WITH n LIMIT 5000 DETACH DELETE n RETURN count(*) AS cnt");
+                    deleted = result.hasNext() ? ((Number) result.next().get("cnt")).intValue() : 0;
+                    tx.commit();
+                }
+            } while (deleted > 0);
 
             // Bulk-load nodes in batches using UNWIND
             // Smaller batches to avoid Neo4j memory pool limit (nodes carry prop_* properties)

src/main/java/io/github/randomcodespace/iq/graph/GraphStore.java

@@ -70,13 +70,17 @@ public void bulkSave(List<CodeNode> nodes) {
         if (nodes.isEmpty()) return;
         long start = System.currentTimeMillis();
 
-        // 1. Clear existing data
+        // 1. Clear existing data in batches to avoid memory pool limit
         log.info("Neo4j: clearing existing graph...");
-        try (Transaction tx = graphDb.beginTx()) {
-            // Batch delete to avoid OOM on huge graphs
-            tx.execute("MATCH (n) DETACH DELETE n");
-            tx.commit();
-        }
+        int deleted;
+        do {
+            try (Transaction tx = graphDb.beginTx()) {
+                var result = tx.execute(
+                        "MATCH (n) WITH n LIMIT 5000 DETACH DELETE n RETURN count(*) AS cnt");
+                deleted = result.hasNext() ? ((Number) result.next().get("cnt")).intValue() : 0;
+                tx.commit();
+            }
+        } while (deleted > 0);
 
         // 2. Create index on id property for fast MATCH during edge creation
         try (Transaction tx = graphDb.beginTx()) {