feat(logs): add instanceIds multi-value filter to /logs endpoint

Adds List<String> instanceIds to LogSearchRequest (null-normalized to
List.of() in compact ctor) and generates an IN clause in both
ClickHouseLogStore.search() and countLogs(), mirroring the existing
sources pattern. LogQueryController parses ?instanceIds= as a
comma-split list. All existing LogSearchRequest call sites updated.
New ClickHouseLogStoreInstanceIdsIT covers: multi-value filter, empty
filter (all rows), null filter (all rows), single-value filter, and
coexistence with the singular instanceId field.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

cameleer-server-core/src/main/java/com/cameleer/server/core/search/LogSearchRequest.java

@@ -9,7 +9,7 @@ import java.util.List;
  * @param q           free-text search across message and stack trace
  * @param levels      log level filter (e.g. ["WARN","ERROR"]), OR-joined
  * @param application application ID filter (nullable = all apps)
- * @param instanceId  agent instance ID filter
+ * @param instanceId  agent instance ID filter (single value; coexists with instanceIds)
  * @param exchangeId  Camel exchange ID filter
  * @param logger      logger name substring filter
  * @param environment optional environment filter (e.g. "dev", "staging", "prod")
@@ -19,6 +19,9 @@ import java.util.List;
  * @param cursor      ISO timestamp cursor for keyset pagination
  * @param limit       page size (1-500, default 100)
  * @param sort        sort direction: "asc" or "desc" (default "desc")
+ * @param instanceIds multi-value instance ID filter (IN clause); scopes logs to one deployment's
+ *                    replicas when provided. Both instanceId and instanceIds may coexist — both
+ *                    conditions apply (AND). Empty/null means no additional filtering.
  */
 public record LogSearchRequest(
         String q,
@@ -33,7 +36,8 @@ public record LogSearchRequest(
         Instant to,
         String cursor,
         int limit,
-        String sort
+        String sort,
+        List<String> instanceIds
 ) {
 
     private static final int DEFAULT_LIMIT = 100;
@@ -45,5 +49,6 @@ public record LogSearchRequest(
         if (sort == null || !"asc".equalsIgnoreCase(sort)) sort = "desc";
         if (levels == null) levels = List.of();
         if (sources == null) sources = List.of();
+        if (instanceIds == null) instanceIds = List.of();
     }
 }