feat(ha-repl-hardening): add observability log statements (task 5.4)

- config_repl.c: INFO at WAL catch-up start with start/target LSN (Req 7.1)
- config_repl.c: INFO at snapshot transfer start and complete with
  checkpoint_lsn and size (Req 7.3)
- ha.c committing_timeout_fn_for_test: add WARN log counting
  n_converged/n_pending before promotion, matching production path (Req 7.5)
- Reqs 7.2 (standby converged INFO) and 7.4 (majority INFO) were
  already present from tasks 3.1 and 5.2 respectively

.kiro/specs/ha-repl-hardening/tasks.md

@@ -193,7 +193,7 @@
   - _Requirements: 6.4_
   - _Boundary: Controller FSM (ha.c)_
 
-- [ ] 5.4 Add observability log statements
+- [x] 5.4 Add observability log statements
   - WAL catch-up start: INFO with start/target LSN — covered by unit test in task 6.2
   - Standby converged: INFO with identity, config_tag, applied_lsn — covered by unit test in task 6.1
   - Snapshot transfer start/complete: INFO with checkpoint_lsn, size — covered by unit test in task 6.4

src/controller/config_repl.c

@@ -1441,6 +1441,11 @@ int ha_stream_wal_to_standby(endpoint_t *ep, const char *wal_path,
     if (standby_lsn >= committed_lsn)
         return 0; /* nothing to stream */
 
+    /* Req 7.1: log WAL catch-up start with start/target LSN */
+    INFO("ha_stream_wal_to_standby: starting WAL catch-up "
+         "start_lsn=%" PRIu64 " target_lsn=%" PRIu64,
+         standby_lsn + 1, committed_lsn);
+
     /* ── Enumerate WAL segment files, sort ascending by first LSN ── */
     DIR *d = opendir(wal_path);
     if (!d)
@@ -1586,6 +1591,11 @@ int ha_send_snapshot_to_standby(endpoint_t *ep, const char *snap_dir,
         return -errno;
     uint64_t total_size = (uint64_t)st.st_size;
 
+    /* Req 7.3: log snapshot transfer start with checkpoint_lsn and size */
+    INFO("ha_send_snapshot_to_standby: snapshot transfer start "
+         "checkpoint_lsn=%" PRIu64 " size=%" PRIu64,
+         checkpoint_lsn, total_size);
+
     FILE *f = fopen(snap_path, "rb");
     if (!f)
         return -errno;
@@ -1647,6 +1657,13 @@ int ha_send_snapshot_to_standby(endpoint_t *ep, const char *snap_dir,
 
     free(buf);
     fclose(f);
+
+    /* Req 7.3: log snapshot transfer complete (on success only) */
+    if (rc == 0)
+        INFO("ha_send_snapshot_to_standby: snapshot transfer complete "
+             "checkpoint_lsn=%" PRIu64 " size=%" PRIu64,
+             checkpoint_lsn, total_size);
+
     return rc;
 }
 

src/controller/ha.c

@@ -2756,8 +2756,24 @@ int committing_timeout_fn_for_test(ha_state_t *ha, cluster_t *c,
         return 0;
     ctrl_role_t role = (ctrl_role_t)atomic_load_explicit(&ha->role,
                                                           memory_order_acquire);
-    if (role == CTRL_PRIMARY_COMMITTING && c != NULL)
+    if (role == CTRL_PRIMARY_COMMITTING) {
-        ha_promote_to_primary(c);
+        /* Count converged vs pending standbys for the WARN log (Req 7.5). */
+        int n_converged = 0;
+        int n_pending   = 0;
+        int n_peers     = ha->n_peers;
+        for (int i = 0; i < n_peers; i++) {
+            if (ha->standby_converged[i])
+                n_converged++;
+            else
+                n_pending++;
+        }
+        WARN("HA: committing timeout — majority convergence not reached within timeout; "
+             "%d/%d standbys converged, %d still pending; "
+             "promoting to PRIMARY in degraded mode (Req 6.4, 7.5)",
+             n_converged, n_peers, n_pending);
+        if (c != NULL)
+            ha_promote_to_primary(c);
+    }
     return 0;
 }