feat(#2038): render http mcp url when HYPERHIVE_MCP_HTTP_PORT set

hive-ag3nt/src/mcp.rs

@@ -2212,14 +2212,27 @@ fn load_extra_mcp() -> std::collections::BTreeMap<String, ExtraMcpServer> {
 #[must_use]
 pub fn render_claude_config(agent_binary: &str, socket: &std::path::Path) -> String {
     let mut servers = serde_json::Map::new();
-    servers.insert(
-        SERVER_NAME.to_owned(),
-        serde_json::json!({
+    // When the harness is configured to run the built-in server as a
+    // persistent streamable-http daemon (loopback port in
+    // `HYPERHIVE_MCP_HTTP_PORT`), point claude at the stable URL instead of
+    // respawning a fresh stdio child each turn. The URL survives the per-turn
+    // claude re-spawn, so there is no per-turn re-registration race for the
+    // hyperhive surface. Extra servers (matrix/bash) stay stdio bridges.
+    let hyperhive_entry = match std::env::var("HYPERHIVE_MCP_HTTP_PORT")
+        .ok()
+        .and_then(|p| p.trim().parse::<u16>().ok())
+    {
+        Some(port) => serde_json::json!({
+            "type": "http",
+            "url": format!("http://127.0.0.1:{port}/mcp"),
+        }),
+        None => serde_json::json!({
             "command": agent_binary,
             "args": ["--socket", socket.display().to_string(), "mcp"],
             "env": {}
         }),
-    );
+    };
+    servers.insert(SERVER_NAME.to_owned(), hyperhive_entry);
     // Auto-inject HYPERHIVE_STATE_DIR so extra MCP servers can resolve the
     // agent's durable state dir without the agent author hard-coding it.
     // User-supplied env takes precedence — we only fill in the missing key.