pub(crate) fn read_task_prompt(jsonl_path: &str) -> Option<String>Expand description
Read just the subagent’s own initial task prompt from the first JSONL
line (a "type":"user" init record) — used by subagent.GenerateName as
the source text for the Haiku naming call. Deliberately bypasses the
events cache/offset machinery read_jsonl_from_offset uses: naming only
ever needs the first line, is called at most once per subagent (cached
via display_name thereafter), and must work even for a subagent whose
events haven’t been scanned into SubagentState yet.
message.content is either a plain string or an array of content blocks
(mirrors the two shapes parse_event_type’s “assistant” arm already
handles) — both are accepted here.