fix(console): bound the pending queue by lines and bytes

The console's pending, not-yet-drained queue was unbounded, so a hidden
Console page that kept receiving verbose daemon-log chunks could grow
without limit.

- Pending lines are now bounded by both a line count and a byte budget.
  The oldest pending lines are dropped once either is exceeded, while
  the newest line is always kept so one huge line is never lost.
- A formatted RPC result is ingested as one block under a single lock,
  so lines from other producers can never interleave inside it.

The front-sequence accounting is also corrected: a pending line dropped
by the cap never entered the visible buffer, so it no longer advances
the front sequence. Only a front eviction or a clear does.

Tests: the line and byte caps keep the newest lines, a single oversized
line survives, a batch appends contiguously, and the front sequence
advances only on a front eviction or clear.

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

src/ui/windows/console_tab.cpp

@@ -2056,12 +2056,14 @@ void ConsoleTab::addFormattedResult(const std::string& result, bool is_error)
 
     // Precompute JSON fold spans over the whole block so each opener line carries the offset
     // to its matching closer (the spans are relative, so they stay valid as the model's line
-    // cap evicts from the front). This block is ingested atomically on the main thread.
+    // cap evicts from the front). The block is ingested under one lock (ingestBatch).
     std::vector<std::string> texts;
     texts.reserve(resultLines.size());
     for (const auto& rl : resultLines) texts.push_back(rl.text);
     const std::vector<int> foldSpans = ComputeConsoleFoldSpans(texts);
 
+    std::vector<ConsoleModelLine> block;
+    block.reserve(resultLines.size());
     for (std::size_t i = 0; i < resultLines.size(); ++i) {
         ConsoleChannel channel = ConsoleChannel::None;
         switch (resultLines[i].role) {
@@ -2072,8 +2074,13 @@ void ConsoleTab::addFormattedResult(const std::string& result, bool is_error)
             case ConsoleResultLineRole::JsonBrace:  channel = ConsoleChannel::JsonBrace; break;
             case ConsoleResultLineRole::Result: break;
         }
-        model_.ingest(resultLines[i].text, channel, foldSpans[i]);
+        ConsoleModelLine ml;
+        ml.text = resultLines[i].text;
+        ml.channel = channel;
+        ml.foldSpan = foldSpans[i];
+        block.push_back(std::move(ml));
     }
+    model_.ingestBatch(std::move(block));
 }
 
 void ConsoleTab::renderStatusHeader(ConsoleCommandExecutor& exec)