Fix: Use Python script to patch agent.py safely (no sed syntax issues)

Dockerfile

@@ -1,4 +1,4 @@
-# CACHE_BUST=20260514_v5_ROOTFIX
+# CACHE_BUST=20260514_v6
 FROM node:20-alpine AS frontend-builder
 RUN apk add --no-cache git
 RUN git clone --depth 1 https://huggingface.co/spaces/smolagents/ml-intern /source
@@ -25,19 +25,9 @@ RUN uv sync --no-dev --frozen
 # Copy frontend
 COPY --from=frontend-builder /source/frontend/dist ./static/
 
-# ====== ROOT FIX: Patch models list directly in agent.py ======
-RUN sed -i 's/DEFAULT_FREE_MODEL_ID = "moonshotai\/Kimi-K2.6"/DEFAULT_FREE_MODEL_ID = "deepseek\/deepseek-chat-v3-0324"/' ./backend/routes/agent.py && \
-    sed -i '/"id": "moonshotai\/Kimi-K2.6"/,/},/c\        {"id": "deepseek/deepseek-chat-v3-0324", "label": "DeepSeek V3", "provider": "openrouter", "tier": "free", "recommended": True},' ./backend/routes/agent.py && \
-    sed -i '/"id": _claude_picker_model_id()/,/},/c\        {"id": "google/gemini-2.0-flash-001", "label": "Gemini 2.0 Flash", "provider": "openrouter", "tier": "free", "recommended": True},' ./backend/routes/agent.py && \
-    sed -i '/"id": "openai\/gpt-5.5"/,/},/c\        {"id": "qwen/qwen3-30b-a3b", "label": "Qwen3 30B", "provider": "openrouter", "tier": "free"},' ./backend/routes/agent.py && \
-    sed -i '/"id": "MiniMaxAI\/MiniMax-M2.7"/,/},/c\        {"id": "anthropic/claude-sonnet-4", "label": "Claude Sonnet 4", "provider": "openrouter", "tier": "pro"},' ./backend/routes/agent.py && \
-    sed -i '/"id": "zai-org\/GLM-5.1"/,/},/c\' ./backend/routes/agent.py && \
-    sed -i '/"id": "deepseek-ai\/DeepSeek-V4-Pro:deepinfra"/,/},/c\' ./backend/routes/agent.py && \
-    echo "✅ Models list patched"
-
-# Verify patch
-RUN grep -A2 "DEFAULT_FREE_MODEL_ID" ./backend/routes/agent.py | head -3
-RUN grep "deepseek-chat-v3" ./backend/routes/agent.py && echo "✅ DeepSeek V3 in models"
+# ====== PATCH: Use Python to safely modify agent.py ======
+COPY patch_agent.py /tmp/patch_agent.py
+RUN python /tmp/patch_agent.py && echo "✅ Agent patched"
 
 # Override main.py and config
 COPY backend/main.py ./backend/main.py