fix: use PUT (not PATCH) for Supabase admin user_metadata update

Supabase Auth admin API requires PUT /auth/v1/admin/users/{id} to update
a user record — PATCH returns 405. Corrects the seed step that sets
kcar's user_type to 'platform_admin'.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

run/initialization/seed_environment.py

@@ -395,7 +395,7 @@ def seed() -> Dict[str, Any]:
     # Fix kcar's auth user_metadata so user_type is "platform_admin", not "teacher".
     # Without this, POST /user/init assigns kcar to the default school on first login.
     try:
-        r = requests.patch(
+        r = requests.put(
             f"{url}/auth/v1/admin/users/{KCAR_ID}",
             headers=headers,
             json={"user_metadata": {"user_type": "platform_admin"}},