fix(enable): catch ENOTDIR hooks paths and pin the nonexistent-path boundary

Review follow-ups: core.hooksPath pointing below a non-directory
(/dev/null/hooks) stat-fails with ENOTDIR and skipped the guidance;
extend the guard to cover it. Add a boundary test proving a
configured-but-missing hooks path still gets created by MkdirAll.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: peyton-alt

cmd/entire/cli/strategy/hooks.go

@@ -10,6 +10,7 @@ import (
 	"runtime"
 	"strings"
 	"sync"
+	"syscall"
 
 	"github.com/entireio/cli/cmd/entire/cli/settings"
 )
@@ -294,7 +295,11 @@ func InstallGitHook(ctx context.Context, silent, localDev, absolutePath bool) (i
 		return 0, err
 	}
 
-	if info, statErr := os.Stat(hooksDir); statErr == nil && !info.IsDir() {
+	info, statErr := os.Stat(hooksDir)
+	notDir := statErr == nil && !info.IsDir()
+	// ENOTDIR: a path component of hooksDir is itself a non-directory
+	// (e.g. core.hooksPath=/dev/null/hooks) — same misconfiguration.
+	if notDir || errors.Is(statErr, syscall.ENOTDIR) {
 		return 0, fmt.Errorf("git resolves the hooks directory to %s, which is not a directory — core.hooksPath is likely set to disable git hooks\n"+
 			"Entire requires git hooks to capture sessions. See where it is set with:\n"+
 			"  git config --show-origin --get-all core.hooksPath\n"+

cmd/entire/cli/strategy/hooks_test.go

@@ -14,6 +14,8 @@ import (
 	"github.com/entireio/cli/cmd/entire/cli/paths"
 )
 
+const goosWindows = "windows"
+
 // readEntireDevScript returns the contents of the committed scripts/entire-dev
 // launcher, located relative to this test file's position in the source tree.
 func readEntireDevScript(t *testing.T) string {
@@ -328,7 +330,7 @@ func TestInstallGitHook_HooksPathNotADirectory(t *testing.T) {
 	}
 
 	hooksPath := "/dev/null"
-	if runtime.GOOS == "windows" {
+	if runtime.GOOS == goosWindows {
 		hooksPath = filepath.Join(tmpDir, "not-a-dir")
 		if err := os.WriteFile(hooksPath, []byte("x"), 0o600); err != nil {
 			t.Fatalf("failed to create non-directory hooks path: %v", err)
@@ -360,6 +362,80 @@ func TestInstallGitHook_HooksPathNotADirectory(t *testing.T) {
 	}
 }
 
+func TestInstallGitHook_HooksPathUnderNonDirectory(t *testing.T) {
+	// core.hooksPath pointing below a non-directory (e.g. /dev/null/hooks)
+	// makes os.Stat fail with ENOTDIR instead of succeeding on a non-dir;
+	// the guidance must fire for this variant too.
+	if runtime.GOOS == goosWindows {
+		t.Skip("ENOTDIR detection is POSIX-specific; Windows falls back to the raw mkdir error")
+	}
+	tmpDir := t.TempDir()
+	ctx := context.Background()
+
+	cmd := exec.CommandContext(ctx, "git", "init")
+	cmd.Dir = tmpDir
+	if err := cmd.Run(); err != nil {
+		t.Fatalf("failed to init git repo: %v", err)
+	}
+	cmd = exec.CommandContext(ctx, "git", "config", "core.hooksPath", "/dev/null/hooks")
+	cmd.Dir = tmpDir
+	if err := cmd.Run(); err != nil {
+		t.Fatalf("failed to set core.hooksPath: %v", err)
+	}
+
+	t.Chdir(tmpDir)
+	ClearHooksDirCache()
+	paths.ClearWorktreeRootCache()
+
+	_, err := InstallGitHook(ctx, true, false, false)
+	if err == nil {
+		t.Fatal("InstallGitHook() should fail when hooks path is under a non-directory")
+	}
+	if !strings.Contains(err.Error(), "core.hooksPath") {
+		t.Errorf("error should name core.hooksPath, got: %s", err)
+	}
+}
+
+func TestInstallGitHook_HooksPathNonexistentIsCreated(t *testing.T) {
+	// A configured-but-missing core.hooksPath is legitimate: the guard must
+	// not fire, and MkdirAll must create the directory and install hooks.
+	tmpDir := t.TempDir()
+	ctx := context.Background()
+
+	cmd := exec.CommandContext(ctx, "git", "init")
+	cmd.Dir = tmpDir
+	if err := cmd.Run(); err != nil {
+		t.Fatalf("failed to init git repo: %v", err)
+	}
+	hooksPath := filepath.Join(tmpDir, "githooks-not-yet-created")
+	cmd = exec.CommandContext(ctx, "git", "config", "core.hooksPath", hooksPath)
+	cmd.Dir = tmpDir
+	if err := cmd.Run(); err != nil {
+		t.Fatalf("failed to set core.hooksPath: %v", err)
+	}
+
+	t.Chdir(tmpDir)
+	ClearHooksDirCache()
+	paths.ClearWorktreeRootCache()
+
+	count, err := InstallGitHook(ctx, true, false, false)
+	if err != nil {
+		t.Fatalf("InstallGitHook() should create a nonexistent hooks path: %v", err)
+	}
+	if count == 0 {
+		t.Fatal("InstallGitHook() should install hooks into the created directory")
+	}
+	for _, hook := range gitHookNames {
+		data, readErr := os.ReadFile(filepath.Join(hooksPath, hook))
+		if readErr != nil {
+			t.Fatalf("expected hook %s in created hooks dir: %v", hook, readErr)
+		}
+		if !strings.Contains(string(data), entireHookMarker) {
+			t.Errorf("hook %s should contain Entire marker", hook)
+		}
+	}
+}
+
 func TestInstallGitHook_WorktreeInstallsInCommonHooks(t *testing.T) {
 	mainRepo, worktreeDir := initHooksWorktreeRepo(t)
 	t.Chdir(worktreeDir)
@@ -1776,7 +1852,7 @@ func TestResolveHookExePath(t *testing.T) {
 		t.Parallel()
 		got, err := resolveHookExePath(exe, func(string) (string, error) {
 			return "", junctionErr
-		}, "windows")
+		}, goosWindows)
 		if err != nil {
 			t.Fatalf("windows should fall back, got error: %v", err)
 		}