test(tui): update walk-depth test for new default depth (#2488)

`workspace_completions_honor_configured_walk_depth` placed its probe file at
component depth 9 and asserted the *default* walk excludes it — true at the
old default (6) but not the new one (10). Move the probe to depth 12 so it
stays past the default while remaining within the explicit deeper walk (16)
and the unlimited (0) cases the test also exercises.

https://claude.ai/code/session_01MQrnh6wHfrEYN5BBdMarC1

crates/tui/src/working_set.rs

@@ -1563,7 +1563,9 @@ mod tests {
     #[test]
     fn workspace_completions_honor_configured_walk_depth() {
         let tmp = TempDir::new().unwrap();
-        let deep_dir = tmp.path().join("a/b/c/d/e/f/g/h");
+        // Sits at component depth 12, past the default walk depth (10) but
+        // within the explicit deeper walk (16) below.
+        let deep_dir = tmp.path().join("a/b/c/d/e/f/g/h/i/j/k");
         std::fs::create_dir_all(&deep_dir).unwrap();
         std::fs::write(deep_dir.join("target.txt"), "target").unwrap();