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, 28 insertions, 2 deletions

diff --git a/src/client/common.rs b/src/client/common.rs
index 3b89d11..ed95291 100644
--- a/src/client/common.rs
+++ b/src/client/common.rs
@@ -403,6 +403,26 @@ pub async fn create_openai_compatible_client_config(
     Ok(Some((model, clients)))
 }
 
+async fn eval_tool_calls_with_ctx(
+    input: &Input,
+    client: &dyn Client,
+    tool_calls: Vec<ToolCall>,
+) -> Result<Vec<ToolResult>> {
+    let path = input.query_path();
+    let subquery_ctx = crate::config::SubqueryContext::from_input(input);
+    let mut ctx = crate::function::EvalToolCallsContext {
+        subquery_ctx: Some(subquery_ctx),
+    };
+    if path.is_empty() {
+        eval_tool_calls(client.global_config(), tool_calls, &mut ctx).await
+    } else {
+        crate::utils::with_query_scope(crate::utils::format_query_path(&path), async {
+            eval_tool_calls(client.global_config(), tool_calls, &mut ctx).await
+        })
+        .await
+    }
+}
+
 pub async fn call_chat_completions(
     input: &Input,
     print: bool,
@@ -432,7 +452,10 @@ pub async fn call_chat_completions(
                     client.global_config().read().print_markdown(&text)?;
                 }
             }
-            Ok((text, eval_tool_calls(client.global_config(), tool_calls)?))
+            Ok((
+                text,
+                eval_tool_calls_with_ctx(input, client, tool_calls).await?,
+            ))
         }
         Err(err) => Err(err),
     }
@@ -463,7 +486,10 @@ pub async fn call_chat_completions_streaming(
             if !text.is_empty() && !text.ends_with('\n') {
                 println!();
             }
-            Ok((text, eval_tool_calls(client.global_config(), tool_calls)?))
+            Ok((
+                text,
+                eval_tool_calls_with_ctx(input, client, tool_calls).await?,
+            ))
         }
         Err(err) => {
             if !text.is_empty() {