refactor: consolidate parse_peers into xce_parse_peers in libxce

Three identical static copies (controller, worker, scheduler) replaced
with a single xce_parse_peers() in src/lib/cluster.c.

The libxce version is the canonical implementation: stores the logical
name from 'name=host:port' syntax so daemons on the same dev host can
identify themselves by name rather than IP address.

src/lib/cluster.c

@@ -14,11 +14,51 @@
 #include <errno.h>
 #include <stddef.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 #include <time.h>
 
 #include "xce/cluster.h"
 
+/* ── Peer list parsing ─────────────────────────────────────────── */
+
+int xce_parse_peers(const char* peers_str, xce_cluster_config_t* cfg)
+{
+    cfg->candidates_count = 0;
+    if (!peers_str || peers_str[0] == '\0')
+        return -1;
+
+    char buf[2048];
+    strncpy(buf, peers_str, sizeof(buf) - 1);
+    buf[sizeof(buf) - 1] = '\0';
+
+    char* saveptr;
+    char* tok = strtok_r(buf, ",", &saveptr);
+    while (tok && cfg->candidates_count < MAX_HA_CANDIDATES) {
+        /* Format: name=host:port  OR  host:port */
+        char* eq    = strchr(tok, '=');
+        char* addr  = eq ? eq + 1 : tok;
+        char* colon = strrchr(addr, ':');
+        if (!colon)
+            return -1;
+        *colon = '\0';
+        xce_candidate_t* cand = &cfg->candidates[cfg->candidates_count];
+        if (eq) {
+            *eq = '\0';
+            strncpy(cand->name, tok, XCE_MAXNAME_LEN - 1);
+            cand->name[XCE_MAXNAME_LEN - 1] = '\0';
+        } else {
+            cand->name[0] = '\0';
+        }
+        strncpy(cand->hostname, addr, XCE_MAXHOSTNAME_LEN - 1);
+        cand->hostname[XCE_MAXHOSTNAME_LEN - 1] = '\0';
+        cand->port = atoi(colon + 1);
+        cfg->candidates_count++;
+        tok = strtok_r(NULL, ",", &saveptr);
+    }
+    return cfg->candidates_count > 0 ? 0 : -1;
+}
+
 /* ── Test seam ─────────────────────────────────────────────────── */
 
 static xce_connect_fn_t s_connect_fn = NULL;