Address PR #594 review feedback

- Fix PassThrough doc comment operation order (set_body before finalize)
- Update function doc to describe actual PassThrough flow (set_body +
  send_to_client, not io::copy)
- Remove dead _enters_early_return variable, replace with comment

Author: aram356

crates/trusted-server-adapter-fastly/src/main.rs

@@ -238,10 +238,7 @@ async fn route_request(
                             // Response already sent via stream_to_client()
                             return None;
                         }
-                        Ok(PublisherResponse::PassThrough {
-                            mut response,
-                            body,
-                        }) => {
+                        Ok(PublisherResponse::PassThrough { mut response, body }) => {
                             // Binary pass-through: reattach body and send via send_to_client().
                             // This preserves Content-Length and avoids chunked encoding overhead.
                             // Fastly streams the body from its internal buffer — no WASM

crates/trusted-server-core/src/publisher.rs

@@ -275,8 +275,8 @@ pub enum PublisherResponse {
         params: OwnedProcessResponseParams,
     },
     /// Non-processable 2xx response (images, fonts, video). The caller must:
-    /// 1. Call `finalize_response()` on the response
-    /// 2. Reattach the body via `response.set_body(body)`
+    /// 1. Reattach the body via `response.set_body(body)`
+    /// 2. Call `finalize_response()` on the response
     /// 3. Call `response.send_to_client()`
     ///
     /// `Content-Length` is preserved — the body is unmodified. Using
@@ -819,10 +819,9 @@ mod tests {
         // pass-through doesn't process, so the host is irrelevant.
         let should_process = false;
         let is_success = true;
-        let request_host_empty = true;
-        // In production: enters the `!should_process || request_host.is_empty()` block,
-        // then the PassThrough guard checks `is_success && !should_process` — host irrelevant.
-        let _enters_early_return = !should_process || request_host_empty;
+        // In production, empty host enters the early-return block via
+        // `!should_process || request_host.is_empty()`. The PassThrough guard
+        // checks `is_success && !should_process` — host is irrelevant.
         let should_pass_through = is_success && !should_process;
         assert!(
             should_pass_through,