Stream OpenAI tool_use as discrete blocks; drop BlockMeta

Close each tool_use on next-index delta (and at finalize) so receivers
see one start/delta/complete trio per tool, matching Anthropic. Log+drop
fragments for already-closed indices.

Remove BlockMeta from the Receiver interface: tool id/name can't be
reliably known at onBlockStart under OpenAI's streaming model. Receivers
get identity from the assembled ContentBlock at onBlockComplete. CLI
renders 'tool: {args} : (name)' accordingly.

1 files changed, 7 insertions, 7 deletions

diff --git a/src/main.zig b/src/main.zig
index a752a12..c1212e8 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -19,7 +19,6 @@ test {
 const Receiver = panto.provider.Receiver;
 const ReceiverVTable = panto.provider.ReceiverVTable;
 const ContentBlockType = panto.provider.ContentBlockType;
-const BlockMeta = panto.provider.BlockMeta;
 const MessageRole = panto.conversation.MessageRole;
 
 /// Receiver that prints streaming deltas to stdout. Thinking blocks are
@@ -50,16 +49,16 @@ const CLIReceiver = struct {
         ptr: *anyopaque,
         block_type: ContentBlockType,
         index: usize,
-        meta: ?BlockMeta,
     ) anyerror!void {
         _ = index;
         const self: *CLIReceiver = @ptrCast(@alignCast(ptr));
         switch (block_type) {
             .Thinking => try self.stdout.writeAll("\x1b[2m[thinking] "),
-            .ToolUse => {
-                const name = if (meta) |m| (m.tool_name orelse "?") else "?";
-                try self.stdout.print("\n\x1b[36m[tool: {s}]\x1b[0m ", .{name});
-            },
+            // Tool name is not known reliably at start time (OpenAI may
+            // stream id/name across fragments). Open with a bare prefix;
+            // the tool name lands at onBlockComplete from the assembled
+            // ContentBlock.
+            .ToolUse => try self.stdout.writeAll("\n\x1b[36mtool: \x1b[0m"),
             else => {},
         }
         try self.file.flush();
@@ -81,7 +80,8 @@ const CLIReceiver = struct {
         const self: *CLIReceiver = @ptrCast(@alignCast(ptr));
         switch (block) {
             .Thinking => try self.stdout.writeAll("\x1b[0m\n"),
-            .ToolUse => try self.stdout.writeAll("\n"),
+            // Append the tool name now that we know it for certain.
+            .ToolUse => |tu| try self.stdout.print("\x1b[36m : ({s})\x1b[0m\n", .{tu.name}),
             else => {},
         }
         try self.file.flush();