Update environment configuration and enhance terminal tool integration

- Modified `.env.example` to set the default terminal environment to 'singularity' and updated Docker and Singularity image references for better compatibility.
- Enhanced `run_mixed_tasks.sh` and `run_terminal_tasks.sh` scripts to utilize the new Singularity setup, including improved logging and cache directory management.
- Introduced functionality in `terminal_tool.py` to automatically build and cache SIF images from Docker URLs, streamlining the execution environment setup.
- Updated logging messages for clarity on image usage and cache directory paths.

.env.example

@@ -30,43 +30,59 @@ NOUS_API_KEY=
 FAL_KEY=
 
 # =============================================================================
-# TERMINAL TOOL CONFIGURATION (mini-swe-agent backend)
+# TERMINAL TOOL CONFIGURATION
 # =============================================================================
 # Backend type: "local", "singularity", "docker", or "modal"
-# - local: Runs directly on your machine (fastest, no isolation)
-# - singularity: Runs in Apptainer/Singularity containers (HPC clusters, no root needed)
-# - docker: Runs in Docker containers (isolated, requires Docker + docker group)
-# - modal: Runs in Modal cloud sandboxes (scalable, requires Modal account)
-TERMINAL_ENV=local
+# Uncomment ONE configuration block below based on your preferred backend.
 
-# Container images (for singularity/docker/modal backends)
-TERMINAL_DOCKER_IMAGE=python:3.11-slim
-TERMINAL_SINGULARITY_IMAGE=docker://python:3.11-slim
-TERMINAL_MODAL_IMAGE=python:3.11-slim
-
-# Working directory inside the container
-TERMINAL_CWD=/tmp
-
-# Default command timeout in seconds
+# -----------------------------------------------------------------------------
+# OPTION 1: Singularity/Apptainer (RECOMMENDED for HPC clusters)
+# - No root required, common on shared systems
+# - Auto-builds and caches SIF images from docker:// URLs
+# - Uses /scratch if available, otherwise /tmp
+# -----------------------------------------------------------------------------
+TERMINAL_ENV=singularity
+TERMINAL_SINGULARITY_IMAGE=docker://nikolaik/python-nodejs:python3.11-nodejs20
+TERMINAL_CWD=/workspace
 TERMINAL_TIMEOUT=60
+# Optional: Override scratch directory (auto-detects /scratch or /tmp)
+# TERMINAL_SCRATCH_DIR=/scratch/myuser/hermes
 
-# Cleanup inactive environments after this many seconds
+# -----------------------------------------------------------------------------
+# OPTION 2: Local execution (FASTEST, but no isolation)
+# - Runs directly on your machine
+# - No containers, no setup required
+# - WARNING: Commands run with your user permissions
+# -----------------------------------------------------------------------------
+# TERMINAL_ENV=local
+# TERMINAL_CWD=/tmp
+# TERMINAL_TIMEOUT=60
+
+# -----------------------------------------------------------------------------
+# OPTION 3: Docker (good isolation, requires Docker)
+# - Requires Docker installed and user in 'docker' group
+# - Each task gets an isolated container
+# -----------------------------------------------------------------------------
+# TERMINAL_ENV=docker
+# TERMINAL_DOCKER_IMAGE=nikolaik/python-nodejs:python3.11-nodejs20
+# TERMINAL_CWD=/workspace
+# TERMINAL_TIMEOUT=60
+
+# -----------------------------------------------------------------------------
+# OPTION 4: Modal (cloud execution, scalable)
+# - Requires Modal account: pip install modal && modal setup
+# - Runs in Modal's cloud sandboxes
+# - Good for scaling to many parallel workers
+# -----------------------------------------------------------------------------
+# TERMINAL_ENV=modal
+# TERMINAL_MODAL_IMAGE=nikolaik/python-nodejs:python3.11-nodejs20
+# TERMINAL_CWD=/workspace
+# TERMINAL_TIMEOUT=60
+
+# Common settings for all backends
 TERMINAL_LIFETIME_SECONDS=300
-
-# Scratch directory for Singularity sandboxes (optional)
-# If not set, uses /scratch (if available) or /tmp
-# TERMINAL_SCRATCH_DIR=/scratch/myuser
-
-# Disk usage warning threshold in GB (default: 500)
 TERMINAL_DISK_WARNING_GB=500
 
-# =============================================================================
-# MODAL CLOUD BACKEND (Optional - for TERMINAL_ENV=modal)
-# =============================================================================
-# Modal uses CLI authentication, not environment variables.
-# Run: pip install modal && modal setup
-# This will authenticate via browser and store credentials locally.
-
 # =============================================================================
 # BROWSER TOOL CONFIGURATION (agent-browser + Browserbase)
 # =============================================================================
@@ -99,11 +115,11 @@ BROWSER_SESSION_TIMEOUT=300
 
 # Morph API Key - For legacy Hecate terminal backend
 # Get at: https://morph.so/
-MORPH_API_KEY=
+# MORPH_API_KEY=
 
 # Hecate VM Settings (only if using terminal-hecate tool)
-HECATE_VM_LIFETIME_SECONDS=300
-HECATE_DEFAULT_SNAPSHOT_ID=snapshot_p5294qxt
+# HECATE_VM_LIFETIME_SECONDS=300
+# HECATE_DEFAULT_SNAPSHOT_ID=snapshot_p5294qxt
 
 # =============================================================================
 # DEBUG OPTIONS