clip-search: fmt + clippy clamp + test AppState arg

Pulls cargo fmt + clippy pass over the new files only — pre-existing
files left untouched even though fmt has drift on them. clamp(1,200)
swaps a manual min/max chain that clippy flagged. test AppState
constructor needed ClipClient::new(None) so the lib-test target
compiles.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/backfill.rs

@@ -273,10 +273,12 @@ pub fn process_clip_backlog(
 
     let candidates: Vec<crate::clip_watch::ClipCandidate> = rows
         .into_iter()
-        .map(|(rel_path, content_hash)| crate::clip_watch::ClipCandidate {
-            rel_path,
-            content_hash,
-        })
+        .map(
+            |(rel_path, content_hash)| crate::clip_watch::ClipCandidate {
+                rel_path,
+                content_hash,
+            },
+        )
         .collect();
 
     crate::clip_watch::run_clip_encoding_pass(