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>

src/agent_tools/filesystem_tools.py

@@ -1,6 +1,7 @@
 import asyncio
 import json
 import os
+import re
 import difflib
 import fnmatch
 import shutil
@@ -16,6 +17,31 @@ _CODENAV_SKIP_DIRS = frozenset({
 _CODENAV_MAX_HITS = 200
 _CODENAV_MAX_LINE = 400
 
+
+def _glob_to_regex(pat: str) -> "re.Pattern":
+    """Translate a forward-slash glob (**, *, ?) into a compiled regex.
+    `**/` matches zero or more complete directories.
+    `*` matches within a single path segment (does not cross /).
+    """
+    i, n, out = 0, len(pat), []
+    while i < n:
+        if pat[i : i + 3] == "**/":
+            out.append("(?:[^/]+/)*")
+            i += 3
+        elif pat[i : i + 2] == "**":
+            out.append(".*")
+            i += 2
+        elif pat[i] == "*":
+            out.append("[^/]*")
+            i += 1
+        elif pat[i] == "?":
+            out.append("[^/]")
+            i += 1
+        else:
+            out.append(re.escape(pat[i]))
+            i += 1
+    return re.compile("".join(out))
+
 def _unified_diff(old: str, new: str, path: str) -> Optional[Dict[str, Any]]:
     if old == new:
         return None
@@ -259,23 +285,38 @@ class GlobTool:
             return {"error": f"glob: {e}", "exit_code": 1}
 
         def _glob():
-            from pathlib import Path
-            base = Path(root)
-            if not base.is_dir():
+            base = os.path.abspath(root)
+            if not os.path.isdir(base):
                 return None, f"glob: {root}: not a directory"
+            norm_pat = pattern.replace("\\", "/")
+            # Fast path: literal pattern (no wildcards) → direct path lookup.
+            if not any(c in norm_pat for c in "*?["):
+                cand = os.path.normpath(os.path.join(base, norm_pat))
+                if os.path.exists(cand):
+                    return [cand], None
+                # Literal not at exact path — fall through to walk so
+                # e.g. "foo.py" still matches at any depth (like rglob).
+            # Compile glob to regex: * stays within one segment, **/ spans dirs.
+            regex = _glob_to_regex(norm_pat)
             matched = []
+            cap = _CODENAV_MAX_HITS * 5
             try:
-                for p in base.rglob(pattern):
-                    if set(p.relative_to(base).parts) & _CODENAV_SKIP_DIRS:
-                        continue
-                    try:
-                        mtime = p.stat().st_mtime
-                    except OSError:
-                        mtime = 0
-                    matched.append((mtime, str(p)))
-                    if len(matched) > _CODENAV_MAX_HITS * 5:
+                for dp, dns, fns in os.walk(base):
+                    # Prune skipped dirs before descending (unlike rglob which
+                    # descends first then filters — fatal on large node_modules).
+                    dns[:] = [d for d in dns if d not in _CODENAV_SKIP_DIRS]
+                    for name in fns + dns:
+                        full = os.path.join(dp, name)
+                        rel = os.path.relpath(full, base).replace(os.sep, "/")
+                        if regex.fullmatch(rel) or regex.fullmatch(name):
+                            try:
+                                mtime = os.stat(full).st_mtime
+                            except OSError:
+                                mtime = 0
+                            matched.append((mtime, full))
+                    if len(matched) > cap:
                         break
-            except (OSError, ValueError) as _e:
+            except OSError as _e:
                 return None, f"glob: {_e}"
             matched.sort(key=lambda t: t[0], reverse=True)
             return [pth for _, pth in matched[:_CODENAV_MAX_HITS]], None