feat: add built-in subquery tool with hierarchical query ids

* Add config options subquery and subquery_max_depth.
* Register an internal subquery function that spawns a fresh LLM query
with the current model configuration but without the full context.
The model selects context numerically (message_indexes) or by text
excerpt (excerpts).
* Subqueries can use tools, including further nested subqueries up to
subquery_max_depth.
* Queries and subqueries get hierarchical ids ([0], [0/1], [0/1/2])
that prefix tool-call prints and spinner messages.

1 files changed, 3 insertions, 1 deletions

diff --git a/src/main.rs b/src/main.rs
index 369a282..b30d022 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -195,10 +195,12 @@ async fn run(config: GlobalConfig, cli: Cli, text: Option<String>) -> Result<()>
 #[async_recursion::async_recursion]
 async fn start_directive(
     config: &GlobalConfig,
-    input: Input,
+    mut input: Input,
     code_mode: bool,
     abort_signal: AbortSignal,
 ) -> Result<()> {
+    let root_id = crate::utils::next_query_id(&[]);
+    input.set_query_path(vec![root_id]);
     let client = input.create_client()?;
     let extract_code = !*IS_STDOUT_TERMINAL && code_mode;
     config.write().before_chat_completion(&input)?;