CB-105: MCP server (bridge_send/bridge_reply/bridge_status) over the REST core

Streamable-HTTP MCP server (io.modelcontextprotocol.sdk:mcp 2.0.0) mounted on the daemon's Jetty at /mcp, exposing three tools as thin adapters over MessageService/Rendezvous — the primary calls bridge_send/bridge_status, the worker calls bridge_reply. Tool logic in unit-testable static methods (parity tests); SDK owns the wire protocol. Resolves the Jackson 2/3 split by pinning jackson-annotations 3.0-rc5 (works for both our Jackson 2.19 and the SDK's Jackson 3). Live-verified: initialize handshake + tools/list return all three tools. Documents the residual Jackson-3 CVE (loopback, trusted clients). 52 tests green, IDE-clean.

bridged/src/test/java/dev/ltms/bridged/mcp/BridgeMcpTest.java

@@ -0,0 +1,81 @@
+package dev.ltms.bridged.mcp;
+
+import dev.ltms.bridged.herdr.AgentControl;
+import dev.ltms.bridged.herdr.FakeHerdr;
+import dev.ltms.bridged.inject.Injector;
+import dev.ltms.bridged.msg.MessageService;
+import dev.ltms.bridged.msg.Rendezvous;
+import io.modelcontextprotocol.spec.McpSchema;
+import org.junit.jupiter.api.Test;
+
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.TimeUnit;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+/**
+ * Parity tests for the MCP tool adapters — they must produce the same outcomes as the REST routes,
+ * since both drive the same {@link MessageService}/{@link Rendezvous}. The MCP wire protocol itself
+ * is the SDK's concern; here we test the thin adapter logic directly.
+ */
+class BridgeMcpTest {
+
+    private final FakeHerdr herdr = new FakeHerdr();
+    private final AgentControl agents = new AgentControl(herdr);
+    private final Rendezvous rendezvous = new Rendezvous();
+    private final MessageService messages = new MessageService(agents, new Injector(agents), rendezvous);
+
+    private static String textOf(McpSchema.CallToolResult r) {
+        return ((McpSchema.TextContent) r.content().getFirst()).text();
+    }
+
+    @Test
+    void sendThenReplyRoundTrips() throws Exception {
+        // bridge_send blocks; bridge_reply resolves it with the worker's structured answer.
+        CompletableFuture<McpSchema.CallToolResult> send = CompletableFuture.supplyAsync(
+                () -> BridgeMcp.send(messages, "term_a", "review this", 4000L));
+
+        McpSchema.CallToolResult reply = BridgeMcp.reply(rendezvous, "term_a", "LGTM");
+        long deadline = System.currentTimeMillis() + 3000;
+        while (Boolean.TRUE.equals(reply.isError()) && System.currentTimeMillis() < deadline) {
+            //noinspection BusyWait
+            Thread.sleep(10);
+            reply = BridgeMcp.reply(rendezvous, "term_a", "LGTM");
+        }
+        assertEquals("delivered", textOf(reply));
+
+        McpSchema.CallToolResult res = send.get(6, TimeUnit.SECONDS);
+        assertNotEquals(Boolean.TRUE, res.isError());
+        assertEquals("LGTM", textOf(res));
+    }
+
+    @Test
+    void sendTimesOutWithAWorkingNote() {
+        McpSchema.CallToolResult res = BridgeMcp.send(messages, "term_a", "hi", 120L);
+        assertNotEquals(Boolean.TRUE, res.isError(), "a timeout is informational, not a tool error");
+        assertTrue(textOf(res).contains("no reply"), "got: " + textOf(res));
+    }
+
+    @Test
+    void sendRejectsMissingArgs() {
+        assertTrue(BridgeMcp.send(messages, null, "hi", null).isError());
+        assertTrue(BridgeMcp.send(messages, "term_a", "  ", null).isError());
+    }
+
+    @Test
+    void replyWithNoPendingSendIsAnError() {
+        McpSchema.CallToolResult res = BridgeMcp.reply(rendezvous, "term_a", "orphan");
+        assertTrue(res.isError());
+        assertTrue(textOf(res).contains("no send is awaiting"));
+    }
+
+    @Test
+    void statusReportsLiveAgentStatus() {
+        FakeHerdr blocked = new FakeHerdr().agentStatus("blocked");
+        AgentControl blockedAgents = new AgentControl(blocked);
+        McpSchema.CallToolResult res = BridgeMcp.status(
+                new MessageService(blockedAgents, new Injector(blockedAgents), rendezvous), "term_a");
+        assertNotEquals(Boolean.TRUE, res.isError());
+        assertEquals("blocked", textOf(res));
+    }
+}

bridged/src/test/java/dev/ltms/bridged/rest/BridgedAppTest.java

@@ -62,7 +62,7 @@ class BridgedAppTest {
         poller.start();
         Rendezvous rendezvous = new Rendezvous();
         MessageService messages = new MessageService(agents, injector, rendezvous);
-        app = new BridgedApp(herdr, workers, messages, rendezvous).build().start("127.0.0.1", 0);
+        app = new BridgedApp(herdr, workers, messages, rendezvous, null).build().start("127.0.0.1", 0);
         return app.port();
     }