Worker (xcecd):
- Add xce_cluster_config_t cluster_cfg field to controller_connector_ctx_t
(controller_connector.h includes xce/cluster.h)
- Populate cc_ctx->cluster_cfg from parsed cluster_cfg after xcecd_start()
sets cc_ctx (main.c, removes the P3 placeholder)
- Replace xcecd_join_cluster() single-shot connect with a candidate-iterating
loop: tries each candidate, calls xcecli_stop() before the next attempt,
falls back to the original single-host path when candidates_count == 0
Scheduler (xce_scheduler):
- Add xce_cluster_config_t cluster_cfg field to xce_scheduler_t
(scheduler.h includes xce/cluster.h)
- Add sched_set_cluster_cfg() setter
- Replace the hardcoded xcecli_start/xcecli_join pair in sched_init() with
the same candidate-iterating pattern; original single-host path preserved
- main.c calls sched_set_cluster_cfg() before sched_init() when --peers given
(removes the P3 placeholder comment)
checking_connection() already calls xcecd_join_cluster() on retry, giving
the worker free reconnect-after-failover behaviour for no additional code.
