Add addUserText helper; update all call sites

Conversation.addUserMessage now takes a []ContentBlock (symmetric with
addAssistantMessage). Introduce a thin addUserText wrapper in agent.zig
for the plain-text case and update every call site in agent.zig and
anthropic_messages_json.zig accordingly.

1 files changed, 5 insertions, 0 deletions

diff --git a/libpanto/src/public.zig b/libpanto/src/public.zig
index f9c2830..277b4ea 100644
--- a/libpanto/src/public.zig
+++ b/libpanto/src/public.zig
@@ -78,6 +78,11 @@ pub const ContentBlock = conversation_mod.ContentBlock;
 pub const Message = conversation_mod.Message;
 pub const MessageRole = conversation_mod.MessageRole;
 pub const TextualBlock = conversation_mod.TextualBlock;
+/// Build a `TextualBlock` (the streaming text buffer used inside content
+/// blocks) from a slice, copying the bytes with `alloc`. The canonical way
+/// for binding code to construct `.Text`/`.Thinking`/tool-result text when
+/// assembling `ContentBlock`s by hand (e.g. for conversation resumption).
+pub const textualBlockFromSlice = conversation_mod.textualBlockFromSlice;
 pub const ThinkingBlock = conversation_mod.ThinkingBlock;
 pub const ToolUseBlock = conversation_mod.ToolUseBlock;
 pub const ToolResultBlock = conversation_mod.ToolResultBlock;