Add Java E2E coverage for session.todos_changed (WIP)

Adds the generated Java bindings for SessionTodosChangedEvent,
PlanSqlTodoDependency, and SessionPlan.readSqlTodosWithDependencies,
plus a Java E2E test mirroring the other 5 SDK languages.

Status: the test currently fails locally - the runtime's
session.todos_changed event is not reaching the Java listener even
though the same scenario passes in Node/.NET/Go/Python/Rust against
the identical CAPI snapshot. Needs follow-up investigation; pushed
as-is so reviewers can see the full 6-language surface.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: SteveSandersonMS

java/src/test/java/com/github/copilot/SessionTodosChangedTest.java

@@ -0,0 +1,79 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *--------------------------------------------------------------------------------------------*/
+
+package com.github.copilot;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.concurrent.TimeUnit;
+
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+import com.github.copilot.generated.SessionEvent;
+import com.github.copilot.generated.SessionTodosChangedEvent;
+import com.github.copilot.generated.rpc.PlanSqlTodoDependency;
+import com.github.copilot.rpc.MessageOptions;
+import com.github.copilot.rpc.PermissionHandler;
+import com.github.copilot.rpc.SessionConfig;
+
+public class SessionTodosChangedTest {
+
+    private static E2ETestContext ctx;
+
+    @BeforeAll
+    static void setup() throws Exception {
+        ctx = E2ETestContext.create();
+    }
+
+    @AfterAll
+    static void teardown() throws Exception {
+        if (ctx != null) {
+            ctx.close();
+        }
+    }
+
+    @Test
+    void firesSessionTodosChangedAndExposesRowsAndDependencies() throws Exception {
+        ctx.configureForTest("session_todos_changed",
+                "fires_session_todos_changed_and_exposes_rows_and_dependencies");
+
+        try (CopilotClient client = ctx.createClient()) {
+            CopilotSession session = client
+                    .createSession(new SessionConfig().setOnPermissionRequest(PermissionHandler.APPROVE_ALL)).get();
+
+            List<SessionEvent> events = Collections.synchronizedList(new ArrayList<>());
+            session.on(events::add);
+
+            session.sendAndWait(new MessageOptions().setPrompt(
+                    "Use the sql tool to execute exactly these statements, in order, with no extra rows:\n"
+                            + "1. INSERT INTO todos (id, title, status) VALUES ('alpha', 'First todo', 'pending');\n"
+                            + "2. INSERT INTO todos (id, title, status) VALUES ('beta', 'Second todo', 'done');\n"
+                            + "3. INSERT INTO todo_deps (todo_id, depends_on) VALUES ('beta', 'alpha');\n"
+                            + "Then stop. Do not insert any other rows or create any other tables."))
+                    .get(120, TimeUnit.SECONDS);
+
+            assertTrue(events.stream().anyMatch(SessionTodosChangedEvent.class::isInstance),
+                    "Should have received at least one session.todos_changed event");
+
+            var result = session.getRpc().plan.readSqlTodosWithDependencies().get(15, TimeUnit.SECONDS);
+            assertEquals(2, result.rows().size());
+            var ids = result.rows().stream().map(row -> row.id()).filter(id -> id != null).sorted().toList();
+
+            assertEquals(List.of("alpha", "beta"), ids);
+            assertTrue(result.dependencies().stream().anyMatch(SessionTodosChangedTest::isBetaDependsOnAlpha),
+                    "Should contain beta -> alpha dependency");
+
+            session.close();
+        }
+    }
+
+    private static boolean isBetaDependsOnAlpha(PlanSqlTodoDependency dependency) {
+        return "beta".equals(dependency.todoId()) && "alpha".equals(dependency.dependsOn());
+    }
+}