Bump the acp-client crate from block/builderbot to pick up the
raw_input forwarding change (builderbot#495). This updates the
MessageWriter trait to accept optional raw_input parameters on
record_tool_call and update_tool_call_title.
Changes:
- src-tauri/Cargo.toml: update acp-client rev to 6cb674a7
- src-tauri/Cargo.lock: updated lockfile
- writer.rs: adapt TauriMessageWriter to new trait signatures
(raw_input ignored for now — no frontend consumer yet)
- dispatcher.rs: forward raw_input from ACP notifications to the
writer, and guard update_tool_call_title on title OR raw_input
being present