fix: auto-seed test users when release command fails on PR envs

The background seeder now creates users directly via DB if login fails,
instead of silently aborting. This handles Railway PR environments where
the releaseCommand may not execute properly.

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

backend/app/main.py

@@ -27,8 +27,20 @@ def _configure_seed_module(mod: object, api_url: str, email: str, password: str)
     mod.ADMIN_PASSWORD = password  # type: ignore[attr-defined]
 
 
+async def _seed_users_directly() -> None:
+    """Seed test users directly via DB if they don't exist yet."""
+    try:
+        from scripts.seed_test_users import main as seed_users
+        logger.info("[seed] Seeding test users directly via DB...")
+        await seed_users()
+        logger.info("[seed] Test users seeded!")
+    except Exception as e:
+        logger.warning(f"[seed] User seeding failed: {e}")
+        raise
+
+
 async def _seed_trees_background() -> None:
-    """Background task: seed all flows via HTTP API after server is ready."""
+    """Background task: seed test users + all flows after server is ready."""
     await asyncio.sleep(5)  # Wait for server to be fully ready
     port = os.environ.get("PORT", "8000")
     api_url = f"http://127.0.0.1:{port}/api/v1"
@@ -37,12 +49,17 @@ async def _seed_trees_background() -> None:
 
     try:
         import httpx
-        # Login to verify admin user exists
+        # Try to login — if it fails, seed users first
         async with httpx.AsyncClient(base_url=api_url, timeout=30) as client:
             login_resp = await client.post("/auth/login/json", json={"email": email, "password": password})
             if login_resp.status_code != 200:
-                logger.warning("[seed] Could not login as admin — skipping flow seeding")
-                return
+                logger.warning("[seed] Admin login failed — seeding users first")
+                await _seed_users_directly()
+                # Retry login after seeding users
+                login_resp = await client.post("/auth/login/json", json={"email": email, "password": password})
+                if login_resp.status_code != 200:
+                    logger.error(f"[seed] Admin login still failing after user seed (status={login_resp.status_code}) — aborting")
+                    return
 
             token = login_resp.json()["access_token"]
             # Check if trees already exist