feat: apply smart fold automatically on page load

Logs with errors now open already smart-folded — every entry within
±25 of an error stays visible, gaps collapse into draggable bars.
Folds can only be expanded individually via per-bar click or
drag; the previous "toggle to unfold everything" path is gone. The
header error-count chip becomes informational only (cursor and
pointer-events stripped so it no longer reads as interactive).

Removed the dead toggleErrors / uncollapseAllErrors / "toggled"
state plumbing.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

web/public/css/iblogs.css

@@ -1153,6 +1153,17 @@ main {
         0 6px 16px color-mix(in srgb, var(--accent) 25%, transparent);
 }
 
+/*
+ * The header error-count chip is informational only — the smart fold is
+ * applied automatically on page load and folds can only be expanded
+ * individually. Strip the .btn cursor / hover affordance so the chip
+ * doesn't read as interactive.
+ */
+#error-toggle {
+    cursor: default;
+    pointer-events: none;
+}
+
 .log-inner .level {
     display: block;
     white-space: pre-wrap;