test(store): tree() leaves out the lock files too (P11c)

Run 13 failed at the same helper: the store holds LockFileEx locks on
wanderbooks.lock and books.lock, which are mandatory on Windows, so
reading them is refused. tree() skips any *.lock and the live SQLite
files at any depth. The other read_dir walkers in the store, cli and gui
tests either read only metadata or copy closed books; the cli harness's
book_files already tolerates a refused read.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HS8WZziDnyxunC23MUxrLp

crates/ledger-store/tests/spec_store.rs

@@ -125,6 +125,12 @@ fn line_types(dir: &Path) -> Vec<String> {
         .collect()
 }
 
+/// Whether `p` is a lock file (`wanderbooks.lock`, `books.lock`, and any
+/// other `*.lock`): it holds no data.
+fn is_lock_file(p: &Path) -> bool {
+    p.extension().is_some_and(|x| x == "lock")
+}
+
 /// Whether `p` is the live SQLite database or one of its companions.
 fn is_live_database(p: &Path) -> bool {
     let name = p.file_name().unwrap().to_string_lossy().into_owned();
@@ -135,18 +141,20 @@ fn is_live_database(p: &Path) -> bool {
             .any(|x| name == format!("{db}{x}"))
 }
 
-/// Every file under `dir` (relative path → bytes), the live database and
-/// its companions left out.
+/// Every file under `dir` (relative path → bytes), the live database, its
+/// companions and the lock files left out.
 fn tree(dir: &Path) -> BTreeMap<PathBuf, Vec<u8>> {
     fn walk(root: &Path, d: &Path, out: &mut BTreeMap<PathBuf, Vec<u8>>) {
         for e in std::fs::read_dir(d).unwrap() {
             let p = e.unwrap().path();
             if p.is_dir() {
                 walk(root, &p, out);
-            } else if p.parent() == Some(root) && is_live_database(&p) {
+            } else if is_live_database(&p) || is_lock_file(&p) {
                 // An open SQLite connection holds byte-range locks on its
-                // database file on Windows: a plain read is refused. The
-                // tests compare the journal, blobs and kept-aside files.
+                // database file on Windows, and so does the store on its
+                // lock files (LockFileEx is mandatory there): a plain read
+                // is refused. The tests compare the journal, blobs and
+                // kept-aside files.
             } else {
                 out.insert(
                     p.strip_prefix(root).unwrap().to_path_buf(),