fix: pin numpy<2.0 to resolve faiss-cpu ImportError

faiss-cpu 1.8.0 uses numpy.core.multiarray which was removed in NumPy 2.0.
Fix: install numpy>=1.24,<2.0 explicitly BEFORE torch and faiss in Dockerfile.

Dockerfile

@@ -1,40 +1,43 @@
 # ── Contexto Backend – Hugging Face Spaces (CPU) ──────────────────────────────
 FROM python:3.10-slim
 
-# HF Spaces requires port 7860
 EXPOSE 7860
 
-# System deps
 RUN apt-get update && apt-get install -y --no-install-recommends \
     gcc g++ git curl \
     && rm -rf /var/lib/apt/lists/*
 
 WORKDIR /app
 
-# ── Step 1: Install PyTorch CPU-only FIRST (separate layer for caching) ────────
-RUN pip install --no-cache-dir --upgrade pip && \
-    pip install --no-cache-dir \
-        torch==2.2.2 \
-        --index-url https://download.pytorch.org/whl/cpu
+# ── Step 1: Upgrade pip ────────────────────────────────────────────────────────
+RUN pip install --no-cache-dir --upgrade pip
 
-# ── Step 2: Copy requirements and install remaining deps ───────────────────────
+# ── Step 2: Pin NumPy <2.0 FIRST (faiss-cpu needs numpy.core, removed in 2.0) ─
+RUN pip install --no-cache-dir "numpy>=1.24.0,<2.0.0"
+
+# ── Step 3: Install PyTorch CPU-only ──────────────────────────────────────────
+RUN pip install --no-cache-dir \
+    torch==2.2.2 \
+    --index-url https://download.pytorch.org/whl/cpu
+
+# ── Step 4: Install remaining dependencies ────────────────────────────────────
 COPY requirements_hf.txt ./requirements_hf.txt
 RUN pip install --no-cache-dir -r requirements_hf.txt
 
-# ── Step 3: Copy all source files ─────────────────────────────────────────────
+# ── Step 5: Copy source ───────────────────────────────────────────────────────
 COPY . .
 
-# ── Step 4: Set HuggingFace cache to writable path ────────────────────────────
+# ── Step 6: HuggingFace cache config ─────────────────────────────────────────
 ENV TRANSFORMERS_CACHE=/app/.cache/huggingface
 ENV HF_HOME=/app/.cache/huggingface
 ENV TOKENIZERS_PARALLELISM=false
 
-# Pre-download T5-small to bake into image (avoids cold-start delay)
+# Pre-download T5-small to bake into image
 RUN python -c "\
 from transformers import T5Tokenizer, T5ForConditionalGeneration; \
 T5Tokenizer.from_pretrained('t5-small'); \
 T5ForConditionalGeneration.from_pretrained('t5-small'); \
-print('T5-small cached.')" || echo "Model pre-download skipped (will download at runtime)"
+print('T5-small cached.')" || echo "Model will download at runtime"
 
-# ── Run FastAPI on port 7860 ───────────────────────────────────────────────────
+# ── Step 7: Run on port 7860 ──────────────────────────────────────────────────
 CMD ["uvicorn", "src.api:app", "--host", "0.0.0.0", "--port", "7860", "--workers", "1"]

requirements_hf.txt

@@ -1,4 +1,9 @@
-# ── Contexto Backend – HF Spaces requirements (torch installed separately in Dockerfile) ──
+# ── Contexto Backend – HF Spaces requirements ─────────────────────────────────
+# NOTE: torch is installed separately in the Dockerfile via --index-url
+
+# NumPy MUST be <2.0 — faiss-cpu and sentence-transformers use numpy.core
+# which was removed in NumPy 2.0
+numpy>=1.24.0,<2.0.0
 
 # NLP core
 transformers==4.40.1
@@ -6,6 +11,7 @@ sentencepiece
 nltk
 
 # Embedding + vector search (RAG)
+# faiss-cpu 1.8.0 requires numpy<2.0 (pinned above)
 sentence-transformers==2.7.0
 faiss-cpu==1.8.0
 
@@ -16,7 +22,6 @@ pydantic==2.7.1
 python-multipart
 
 # Text processing
-numpy
 scikit-learn
 rouge-score
 
@@ -25,8 +30,3 @@ deep-translator==1.11.4
 
 # Document parsing helpers
 requests
-
-# Document reading
-python-docx
-PyMuPDF
-mammoth