feat(controller): clusterconfig-schema-split task 3 — fix test fixtures for shrunk cluster_config_t

Drops the two cfg.port = ...; struct-literal assignments in
test_commit_barrier_rollout.c and test_config_repl.c (removed field, task
1.2). Repo-wide sweep found no other genuine cluster_config_t literal
referencing a removed field.

Full clean build now succeeds (153/153 targets) and controller_unit_test
passes 976/976 with zero new failures.

.kiro/specs/clusterconfig-schema-split/tasks.md

@@ -53,7 +53,7 @@
   - _Depends: 2.1_
   - _Boundary: myconf.c, config_repl.c_
 
-- [ ] 3. (P) Update struct-literal test fixtures for the shrunk `cluster_config_t`
+- [x] 3. (P) Update struct-literal test fixtures for the shrunk `cluster_config_t`
   - Drop the `cfg.port = 9990;` literal at `test_commit_barrier_rollout.c:1359`
   - Drop the `cfg.port = 9991;` literal at `test_config_repl.c:983`
   - Grep the full tree for any other direct `cluster_config_t` struct-literal reference to a removed field and update each the same way

src/controller/testsuite/test_commit_barrier_rollout.c

@@ -1356,7 +1356,6 @@ static uint8_t *cb5_make_config_blob(size_t *len_out)
 
     memset(&cfg, 0, sizeof(cfg));
     cfg.clustername       = (char *)"cb5-upgrade";
-    cfg.port              = 9990;
     cfg.config_generation = 1;
 
     capn_init_malloc(&cap);

src/controller/testsuite/test_config_repl.c

@@ -980,7 +980,6 @@ static uint8_t *t43_make_config_blob(size_t *len_out)
 
     memset(&cfg, 0, sizeof(cfg));
     cfg.clustername       = (char *)"t43-upgrade";
-    cfg.port              = 9991;
     cfg.config_generation = 1;
 
     capn_init_malloc(&cap);