harness: typing indicator during agent turns (keepalive refreshes 60s window, cleared on reply)

src/matrix.zig

@@ -292,6 +292,33 @@ fn markdownToHtml(alloc: std.mem.Allocator, md: []const u8) ![]u8 {
     return out.toOwnedSlice(alloc);
 }
 
+
+/// Typing notification. timeout_ms: how long the indicator lasts server-side
+/// (refresh periodically for long turns). typing=false clears it immediately.
+pub fn setTyping(alloc: std.mem.Allocator, io: Io, token: []const u8, user_id: []const u8, room: []const u8, typing: bool, timeout_ms: i64) void {
+    var url_buf: std.ArrayListUnmanaged(u8) = .empty;
+    defer url_buf.deinit(alloc);
+    const user_esc = std.fmt.allocPrint(alloc, "{s}", .{user_id}) catch return;
+    defer alloc.free(user_esc);
+    // user ids contain chars that are fine unescaped in a path segment for
+    // conduwuit, but encode the ':' minimally
+    var user_path: std.ArrayListUnmanaged(u8) = .empty;
+    defer user_path.deinit(alloc);
+    for (user_esc) |ch| {
+        if (ch == ':') user_path.appendSlice(alloc, "%3A") catch return else user_path.append(alloc, ch) catch return;
+    }
+    const url = std.fmt.allocPrint(alloc, "{s}/_matrix/client/v3/rooms/{s}/typing/{s}", .{ HOMESERVER, room, user_path.items }) catch return;
+    defer alloc.free(url);
+    var payload: std.ArrayListUnmanaged(u8) = .empty;
+    defer payload.deinit(alloc);
+    const body = if (typing)
+        std.fmt.allocPrint(alloc, "{{\"typing\":true,\"timeout\":{d}}}", .{timeout_ms}) catch return
+    else
+        alloc.dupe(u8, "{\"typing\":false}") catch return;
+    defer alloc.free(body);
+    _ = httpRaw(alloc, io, "PUT", url, token, "application/json", body) catch null;
+}
+
 pub fn sendText(alloc: std.mem.Allocator, io: Io, token: []const u8, room: []const u8, body: []const u8) ![]u8 {
     const ts = Io.Clock.now(.real, io).nanoseconds;
     const url = try std.fmt.allocPrint(alloc, "{s}/_matrix/client/v3/rooms/{s}/send/m.room.message/infr-{d}", .{ HOMESERVER, room, ts });