fix(tools): prune skipped dirs before descending in glob tool (#4538)

* fix(tools): prune skipped dirs before descending in glob tool

GlobTool used pathlib.Path.rglob which descends into every directory
(including node_modules, .git, dist, etc.) and filters AFTER the walk.
On repos with large junk directories this causes the glob tool to hang
for minutes.

Replace rglob with os.walk that prunes _CODENAV_SKIP_DIRS before
descending — matching the approach GrepTool already uses. Also add a
fast path for literal patterns (no wildcards → direct path lookup).

Fixes #4493

* fix(tools): use regex glob matching to fix * semantics and literal fallback

Replace fnmatch with _glob_to_regex so that * stays within a single
path segment (matching pathlib/rglob semantics) and **/ spans zero or
more directories.  Literal patterns now fall through to os.walk when
the direct path lookup misses, so e.g. 'foo.py' still finds files at
any depth.

Add tests for:
- bare literal matching in subdirectories
- multi-segment single-star patterns (sub/*.txt)
- * not crossing / boundaries
- ** matching at arbitrary depth

Closes #4493

---------

Co-authored-by: michaelxer <michaelxer@users.noreply.github.com>

tests/test_code_nav_tools.py

@@ -24,6 +24,9 @@ def repo():
         os.mkdir(os.path.join(root, "sub"))
         with open(os.path.join(root, "sub", "b.txt"), "w") as f:
             f.write("nothing\nNEEDLE upper\n")
+        os.mkdir(os.path.join(root, "sub", "deep"))
+        with open(os.path.join(root, "sub", "deep", "c.py"), "w") as f:
+            f.write("# deep python\n")
         os.mkdir(os.path.join(root, "node_modules"))
         with open(os.path.join(root, "node_modules", "dep.py"), "w") as f:
             f.write("needle in dep\n")
@@ -107,6 +110,37 @@ def test_glob_requires_pattern(repo):
     assert r["exit_code"] == 1
 
 
+def test_glob_literal_in_subdir(repo):
+    """Bare literal should match at any depth (like rglob), not only at root."""
+    r = _run("glob", f'{{"pattern": "b.txt", "path": "{repo}"}}')
+    assert r["exit_code"] == 0
+    assert "b.txt" in r["output"]
+
+
+def test_glob_multi_segment_single_star(repo):
+    """sub/*.txt matches sub/b.txt but NOT sub/deep/c.py (single * stays in one segment)."""
+    r = _run("glob", f'{{"pattern": "sub/*.txt", "path": "{repo}"}}')
+    assert r["exit_code"] == 0
+    assert "b.txt" in r["output"]
+    assert "c.py" not in r["output"]
+
+
+def test_glob_star_does_not_cross_slash(repo):
+    """src/*.py must NOT match src/a/b/x.py — * is single-segment only."""
+    r = _run("glob", f'{{"pattern": "sub/*.py", "path": "{repo}"}}')
+    assert r["exit_code"] == 0
+    # sub/ has no .py directly, only sub/deep/c.py — should NOT match
+    assert "No files matching" in r["output"]
+
+
+def test_glob_double_star_matches_deep(repo):
+    """**/*.py should match files at any depth."""
+    r = _run("glob", f'{{"pattern": "**/*.py", "path": "{repo}"}}')
+    assert r["exit_code"] == 0
+    assert "a.py" in r["output"]
+    assert "c.py" in r["output"]
+
+
 # ── ls ────────────────────────────────────────────────────────────────────
 
 def test_ls_lists_entries(repo):