Latch a terminal on sent-dict mirror overflow

ensureSentDictCapacity threw a bare LineSenderException when the
lifetime-monotonic sent-dictionary mirror would exceed
MAX_SENT_DICT_BYTES. accumulateSentDict runs after the frame's
sendBinary, so that throw unwound to ioLoop -> fail() -> connectLoop
with running still true, which reconnected and replayed the same frame;
the mirror never shrinks, so the replay re-overflowed and the loop
reconnected again -- an unbounded livelock instead of the loud failure
the ceiling promises.

recordFatal now flips running=false before the throw, so connectLoop's
!running guard winds the loop down and checkError() surfaces the
terminal to the producer. This matches sendCatchUpChunk's guard for the
same ceiling. The throw stays, to unwind past the pending copyMemory.
The path needs ~100M+ distinct symbols on one connection to reach, so
it is defensive; the producer's GlobalSymbolDictionary would OOM first.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: glasstiger

core/src/main/java/io/questdb/client/cutlass/qwp/client/sf/cursor/CursorWebSocketSendLoop.java

@@ -2137,8 +2137,19 @@ private void ensureSentDictCapacity(long required) {
             return;
         }
         if (required > MAX_SENT_DICT_BYTES) {
-            throw new LineSenderException("symbol dictionary mirror exceeds the maximum size ["
+            // Latch a terminal, do NOT just throw: accumulateSentDict runs AFTER
+            // the frame's sendBinary, so a bare throw unwinds to ioLoop -> fail()
+            // -> connectLoop, which (running still true) reconnects and replays the
+            // same frame, which re-overflows the never-shrinking mirror -- an
+            // unbounded reconnect livelock rather than the "fails loudly" the
+            // MAX_SENT_DICT_BYTES ceiling promises. recordFatal flips running=false
+            // so connectLoop's !running guard winds the loop down and checkError()
+            // surfaces the terminal, matching sendCatchUpChunk's guard for the same
+            // ceiling. The throw still unwinds past the pending copyMemory.
+            LineSenderException err = new LineSenderException("symbol dictionary mirror exceeds the maximum size ["
                     + "required=" + required + ", max=" + MAX_SENT_DICT_BYTES + ']');
+            recordFatal(err);
+            throw err;
         }
         // Grow in long to avoid the capacity*2 int overflow (negative) that would
         // otherwise degrade the doubling near 1 GB; clamp to the int ceiling.