fix: quote json/jsonb/bpchar/uuid values in migration INSERTs

The migration INSERT builder's switch quoted varchar/text/char/clob/date/time
but let everything else fall to a default that emits rs.getString() unquoted
(correct for numerics, broken for strings). A pg->SQL Server pull of a jsonb
column failed with "Incorrect syntax near 'volume_bucket'" — the JSON text's
embedded double-quotes were read as a SQL identifier. Quote json/jsonb, plus
bpchar (PG char(n)) and uuid, like varchar.

Note: the default case still emits unquoted; other unhandled string types
(e.g. bool->'t'/'f') would need similar handling or a quote-by-default flip.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

jrunner/src/main/java/jrunner/jrunner.java

@@ -208,6 +208,15 @@ public class jrunner {
         }
         try {
             scon = DriverManager.getConnection(scu, scn, scp);
+            // Migration mode only: PostgreSQL ignores setFetchSize unless autoCommit
+            // is false — without this it buffers the ENTIRE result set into memory
+            // (OOM on big tables). The migration source is read-only, so never
+            // committing is harmless. Do NOT do this in query mode: callers run
+            // committed DDL/DML through query mode, and autoCommit=false would roll
+            // those statements back on connection close.
+            if (!queryMode) {
+                scon.setAutoCommit(false);
+            }
         } catch (SQLException e) {
             System.out.println("issue connecting to source:");
             e.printStackTrace();
@@ -302,7 +311,16 @@ public class jrunner {
                 nr = "";
                 for (int i = 1; i <= cols; i++){
                     switch (dtn[i].toUpperCase()){
+                        // PG string-ish types that otherwise fall to the default
+                        // case and get emitted UNQUOTED (breaking the INSERT):
+                        // jsonb/json carry embedded quotes, bpchar is PG's char(n),
+                        // uuid is a quoted literal. Quote them like varchar.
+                        case "JSON":
+                        case "JSONB":
+                        case "BPCHAR":
+                        case "UUID":
                         case "VARCHAR":
+                        case "NVARCHAR":
                             nc = rs.getString(i);
                             if (rs.wasNull() || nc == null) {
                                 nc = "NULL";
@@ -313,6 +331,7 @@ public class jrunner {
                             nc = "'" + nc + "'";
                             break;
                         case "TEXT":
+                        case "NTEXT":
                             nc = rs.getString(i);
                             if (rs.wasNull() || nc == null) {
                                 nc = "NULL";
@@ -323,6 +342,7 @@ public class jrunner {
                             nc = "'" + nc + "'";
                             break;
                         case "CHAR":
+                        case "NCHAR":
                             nc = rs.getString(i);
                             if (rs.wasNull() || nc == null) {
                                 nc = "NULL";
@@ -333,6 +353,7 @@ public class jrunner {
                             nc = "'" + nc + "'";
                             break;
                         case "CLOB":
+                        case "NCLOB":
                             nc = rs.getString(i);
                             if (rs.wasNull() || nc == null) {
                                 nc = "NULL";