feat: add client-side Level/Event filters to Log Entries

The backend rejects `level`/`event` as x:Log/query filter conditions
(unsupportedFilter), even though both are already returned per row.
Since a real fix requires backend changes outside this repo, the two
filters are injected into the schema client-side (clientOnly flag) and
applied entirely in the browser: excluded from the JMAP filter sent to
the server, and used to narrow an eagerly-fetched, locally-paginated
result set instead.

Also makes large enum filters (Event has 634 values) render as a
searchable Combobox instead of a plain Select, generically for any
list with more than 15 enum options.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/lib/logFilters.ts

@@ -0,0 +1,35 @@
+/*
+ * SPDX-FileCopyrightText: 2020 Stalwart Labs LLC <hello@stalw.art>
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-SEL
+ */
+
+import type { Schema } from '@/types/schema';
+
+/**
+ * The Stalwart JMAP backend rejects `level`/`event` as filter conditions on
+ * `x:Log/query` (`unsupportedFilter`), even though both properties are
+ * already returned per row. Until the backend adds real support, these two
+ * filters are appended client-side and applied entirely in the browser
+ * (see the `clientOnly` flag consumed by DynamicList) instead of being sent
+ * to the server.
+ */
+export function withClientLogFilters(schema: Schema): Schema {
+  const logList = schema.lists['x:Log'];
+  if (!logList || !schema.enums['TracingLevel'] || !schema.enums['EventType']) return schema;
+
+  return {
+    ...schema,
+    lists: {
+      ...schema.lists,
+      'x:Log': {
+        ...logList,
+        filters: [
+          ...(logList.filters ?? []),
+          { type: 'enum', field: 'level', enumName: 'TracingLevel', label: 'Level', clientOnly: true },
+          { type: 'enum', field: 'event', enumName: 'EventType', label: 'Event', clientOnly: true },
+        ],
+      },
+    },
+  };
+}