refactor(phase4): address CodeRabbit review

- Pin uv version in Dockerfile and add non-root user
- Use OrchestratorConfig for timeout in app.py
- Use timezone.utc for timestamps in models.py

Dockerfile

@@ -10,7 +10,7 @@ RUN apt-get update && apt-get install -y \
     && rm -rf /var/lib/apt/lists/*
 
 # Install uv
-RUN pip install uv
+RUN pip install uv==0.5.4
 
 # Copy project files
 COPY pyproject.toml .
@@ -21,9 +21,17 @@ COPY README.md .
 # Install dependencies
 RUN uv sync --frozen --no-dev
 
+# Create non-root user
+RUN useradd --create-home --shell /bin/bash appuser
+USER appuser
+
 # Expose port
 EXPOSE 7860
 
+# Health check
+HEALTHCHECK --interval=30s --timeout=10s --start-period=5s --retries=3 \
+    CMD curl -f http://localhost:7860/ || exit 1
+
 # Set environment variables
 ENV GRADIO_SERVER_NAME=0.0.0.0
 ENV GRADIO_SERVER_PORT=7860

src/app.py

@@ -24,10 +24,16 @@ def create_orchestrator(use_mock: bool = False) -> Orchestrator:
     Returns:
         Configured Orchestrator instance
     """
+    # Create orchestrator config
+    config = OrchestratorConfig(
+        max_iterations=5,
+        max_results_per_tool=10,
+    )
+
     # Create search tools
     search_handler = SearchHandler(
         tools=[PubMedTool(), WebTool()],
-        timeout=30.0,
+        timeout=config.search_timeout,
     )
 
     # Create judge (mock or real)
@@ -37,12 +43,6 @@ def create_orchestrator(use_mock: bool = False) -> Orchestrator:
     else:
         judge_handler = JudgeHandler()
 
-    # Create orchestrator
-    config = OrchestratorConfig(
-        max_iterations=5,
-        max_results_per_tool=10,
-    )
-
     return Orchestrator(
         search_handler=search_handler,
         judge_handler=judge_handler,

src/utils/models.py

@@ -1,6 +1,6 @@
 """Data models for the Search feature."""
 
-from datetime import datetime
+from datetime import UTC, datetime
 from typing import Any, ClassVar, Literal
 
 from pydantic import BaseModel, Field
@@ -109,7 +109,7 @@ class AgentEvent(BaseModel):
     ]
     message: str
     data: Any = None
-    timestamp: datetime = Field(default_factory=datetime.now)
+    timestamp: datetime = Field(default_factory=lambda: datetime.now(UTC))
     iteration: int = 0
 
     def to_markdown(self) -> str: