fix: cargo fmt the merge_workspace validation code

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

server/src/http/mcp/shell_tools.rs

@@ -85,9 +85,7 @@ fn validate_working_dir(working_dir: &str, ctx: &AppContext) -> Result<PathBuf,
 
     // Also allow the merge workspace so mergemaster can fix conflicts.
     let merge_workspace = project_root.join(".huskies").join("merge_workspace");
-    let canonical_mw = merge_workspace
-        .canonicalize()
-        .unwrap_or_default();
+    let canonical_mw = merge_workspace.canonicalize().unwrap_or_default();
 
     if !canonical_wd.starts_with(&canonical_wt)
         && !(!canonical_mw.as_os_str().is_empty() && canonical_wd.starts_with(&canonical_mw))