fix(mcp): keep an older successful refresh when a newer one fails

Refreshes commit unless a newer one already has, so an out-of-order completion
never overwrites newer tools, and a failed newer refresh no longer discards an
older one that succeeded.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0172qrhMa5TQgETASi5hxMqD

Author: Ralph Sto. Domingo

packages/opencode/src/mcp/index.ts

@@ -758,22 +758,25 @@ export const layer = Layer.effect(
       )
 
       if (!client.getServerCapabilities()?.tools) return
-      // altimate_change start — overlapping refreshes: only the latest one commits.
+      // altimate_change start — overlapping refreshes: an older one never overwrites a newer.
       let refreshes = 0
+      let committed = 0
       // altimate_change end
       client.setNotificationHandler(ToolListChangedNotificationSchema, async () => {
         if (s.clients[name] !== client || s.status[name]?.status !== "connected") return
 
         // altimate_change start — matches create(): McpCatalog.defsWithMeta() tolerates
         // annotation-null tools on a live tool-list refresh (#792) and hands back the
-        // listing with its own `_meta`. A refresh that a later one overtook while it
-        // awaited drops its listing, so an out-of-order completion never writes an
-        // older tool set or report over a newer one. (bot review)
+        // listing with its own `_meta`. A refresh commits unless a newer one already
+        // has, so an out-of-order completion never writes an older tool set or report
+        // over a newer one, and a newer refresh that fails does not discard an older
+        // one that succeeded. (bot review)
         const refresh = ++refreshes
         const listing = await bridge.promise(McpCatalog.defsWithMeta(client, timeout))
         if (!listing) return
         if (s.clients[name] !== client || s.status[name]?.status !== "connected") return
-        if (refresh !== refreshes) return
+        if (refresh < committed) return
+        committed = refresh
         // altimate_change end
 
         // altimate_change start — tools and THEIR report land in one statement: the