fix: update VM_IMAGE to use the base Ubuntu image instead of Dockerfile

docker/Dockerfile.vm

@@ -1,14 +0,0 @@
-FROM ubuntu:22.04
-
-# Install core utilities and Python
-RUN apt-get update \
-    && apt-get install -y --no-install-recommends \
-        python3 \
-        python3-pip \
-        sudo \
-        curl \
-        git \
-        build-essential \
-    && rm -rf /var/lib/apt/lists/*
-
-CMD ["sleep", "infinity"]

src/config.py

@@ -9,7 +9,7 @@ OLLAMA_HOST: Final[str] = os.getenv("OLLAMA_HOST", "http://localhost:11434")
 MAX_TOOL_CALL_DEPTH: Final[int] = 5
 NUM_CTX: Final[int] = int(os.getenv("OLLAMA_NUM_CTX", "16000"))
 UPLOAD_DIR: Final[str] = os.getenv("UPLOAD_DIR", str(Path.cwd() / "uploads"))
-VM_IMAGE: Final[str] = os.getenv("VM_IMAGE", "docker/Dockerfile.vm")
+VM_IMAGE: Final[str] = os.getenv("VM_IMAGE", "ubuntu:22.04")
 
 SYSTEM_PROMPT: Final[str] = (
     "You are Starlette, a professional AI assistant with advanced tool orchestration. "