fix(install): recognise junctions at skill-link paths

better_memory/cli/install_hooks.py

@@ -244,10 +244,22 @@ def install_skill_symlinks() -> None:
         if not source.is_dir():
             continue
         link = user_skills_dir / skill_name
-        if link.is_symlink():
+        # Junctions (mklink /J — creatable without Developer Mode, so a
+        # plausible manual workaround for the symlink-privilege WARN below)
+        # report is_symlink() == False but ARE links: resolve() follows them
+        # and shutil.rmtree refuses them outright ("Cannot call rmtree on a
+        # symbolic link"), which used to crash the installer before the JSON
+        # writes — a total install failure. Treat them exactly like symlinks.
+        if link.is_symlink() or os.path.isjunction(link):
             if link.resolve() == source.resolve():
                 continue  # Already correct — nothing to do.
-            link.unlink()
+            try:
+                link.unlink()
+            except (OSError, PermissionError):
+                # Directory junctions on some Python/Windows combinations
+                # reject unlink(); rmdir removes the link itself and can
+                # never touch the target's contents.
+                os.rmdir(link)
         elif link.exists():
             if link.is_file():
                 link.unlink()

tests/e2e/test_install_hooks.py

@@ -713,3 +713,47 @@ def test_symlink_already_correct_is_noop(harness: InstallHarness) -> None:
     assert (after.st_ino, after.st_ctime_ns) == before_identity, (
         "already-correct symlink was recreated instead of no-op'd"
     )
+
+
+# --------------------------------- A7: junction at the skill-link path
+
+
+def test_junction_skill_link_is_recognised_and_skipped(
+    harness: InstallHarness,
+) -> None:
+    """A junction (mklink /J) pointing at the right skill source must be
+    treated as an already-correct link, not a real directory.
+
+    Junctions report ``is_symlink() == False`` but ``shutil.rmtree`` refuses
+    them, so the old dir-branch crashed the installer BEFORE the JSON writes
+    — a total install failure triggered by the very workaround (junctions
+    need no Developer Mode) a user on locked-down Windows would reach for.
+    """
+    if not hasattr(os.path, "isjunction"):
+        pytest.skip("os.path.isjunction requires Python 3.12+")
+
+    repo_skills = Path(__file__).resolve().parents[2] / ".claude" / "skills"
+    source = repo_skills / SKILL_NAMES[0]
+    skills_dir = harness.home / ".claude" / "skills"
+    skills_dir.mkdir(parents=True, exist_ok=True)
+    junction = skills_dir / SKILL_NAMES[0]
+
+    proc = subprocess.run(  # noqa: S603 - fixed argv, test harness
+        ["cmd", "/c", "mklink", "/J", str(junction), str(source)],
+        capture_output=True, text=True,
+    )
+    if proc.returncode != 0:
+        pytest.skip(f"cannot create junction here: {proc.stderr.strip()}")
+    assert os.path.isjunction(junction)
+
+    result = harness.run()
+    assert result.returncode == 0, result.stderr
+    assert "Cannot call rmtree" not in result.stderr
+
+    # Both configs written despite the pre-existing junction.
+    settings = json.loads(
+        (harness.home / ".claude" / "settings.json").read_text(encoding="utf-8")
+    )
+    assert_managed_shapes(settings)
+    # The junction survived untouched (it already pointed at the source).
+    assert os.path.isjunction(junction)