fix: correct detect install method when running from a subtree

hermes_cli/banner.py

@@ -322,7 +322,7 @@ def check_for_updates() -> Optional[int]:
     # (branding.tsx, guarded on `typeof === 'number' && > 0`) show nothing.
     try:
         from hermes_cli.config import detect_install_method, get_project_root
-        if detect_install_method() == "docker":
+        if detect_install_method(get_project_root()) == "docker":
             return None
     except Exception:
         pass
@@ -885,7 +885,7 @@ def build_welcome_banner(console: "Console", model: str, cwd: str,
             is_unsupported_install_method,
             get_project_root
         )
-        _install_method = detect_install_method()
+        _install_method = detect_install_method(get_project_root())
         if is_unsupported_install_method(_install_method):
             right_lines.append(
                 f"[bold yellow]⚠ {format_unsupported_install_warning(_install_method)}[/]"

hermes_cli/config.py

@@ -439,8 +439,20 @@ def detect_install_method(project_root: Optional[Path] = None) -> str:
     managed = get_managed_system()
     if managed:
         return managed.lower().replace(" ", "-")
-    if (root / ".git").is_dir():
+    
+    # detect git repo installs (normal installer, development env)
+    git_path = root / ".git"
+    if git_path.is_dir():
         return "git"
+
+    # detect git repo installs from worktrees
+    if git_path.is_file():
+        try:
+            content = git_path.read_text(encoding="utf-8").strip()
+            if content.startswith("gitdir:"):
+                return "git"
+        except OSError:
+            pass
     return "pip"
 
 
@@ -526,7 +538,7 @@ def recommended_update_command() -> str:
     managed_cmd = get_managed_update_command()
     if managed_cmd:
         return managed_cmd
-    method = detect_install_method()
+    method = detect_install_method(get_project_root())
     return recommended_update_command_for_method(method)