Fix HF startup: add torch deps and lazy-load T5 imports

psq_rag/llm/rewrite_local_t5.py

@@ -5,9 +5,6 @@ import threading
 from pathlib import Path
 from typing import Optional
 
-import torch
-from transformers import AutoModelForSeq2SeqLM, AutoTokenizer
-
 _LOCK = threading.Lock()
 _MODEL = None
 _TOKENIZER = None
@@ -32,6 +29,10 @@ def _load_model(model_dir: Path):
         if not model_dir.is_dir():
             raise FileNotFoundError(f"T5 rewrite model directory not found: {model_dir}")
 
+        # Lazy import so missing deps never crash app import/startup.
+        import torch
+        from transformers import AutoModelForSeq2SeqLM, AutoTokenizer
+
         tokenizer = AutoTokenizer.from_pretrained(str(model_dir), local_files_only=True, use_fast=False)
         model = AutoModelForSeq2SeqLM.from_pretrained(str(model_dir), local_files_only=True)
         model.eval()
@@ -55,6 +56,8 @@ def local_t5_rewrite_prompt(
         return ""
 
     try:
+        import torch
+
         resolved_dir = _resolve_model_dir(model_dir).resolve()
         model, tokenizer = _load_model(resolved_dir)
         task_prefix = os.environ.get("PSQ_T5_REWRITE_TASK_PREFIX", "caption_to_tags: ").strip()

requirements.txt

@@ -12,3 +12,6 @@ huggingface_hub<1.0
 rapidfuzz>=3.0
 langchain-core>=0.3,<0.4
 langchain-openai>=0.2,<0.4
+torch
+transformers>=4.46,<5
+sentencepiece