/auto (#16696)

Add `/auto` behind a feature flag that's disabled for now, even for
staff.

We've decided on a different design for context inference, but there are
parts of /auto that will be useful for that, so we want them in the code
base even if they're unused for now.

Release Notes:

- N/A

---------

Co-authored-by: Antonio Scandurra <me@as-cii.com>
Co-authored-by: Marshall Bowers <elliott.codes@gmail.com>

crates/collab/src/llm.rs

@@ -402,12 +402,12 @@ async fn perform_completion(
         LanguageModelProvider::Zed => {
             let api_key = state
                 .config
-                .qwen2_7b_api_key
+                .runpod_api_key
                 .as_ref()
                 .context("no Qwen2-7B API key configured on the server")?;
             let api_url = state
                 .config
-                .qwen2_7b_api_url
+                .runpod_api_summary_url
                 .as_ref()
                 .context("no Qwen2-7B URL configured on the server")?;
             let chunks = open_ai::stream_completion(