fix: Database-first cluster status detection + Stop button clarification

CRITICAL FIX (Nov 30, 2025):
- Dashboard showed 'idle' despite 22+ worker processes running
- Root cause: SSH-based worker detection timing out
- Solution: Check database for running chunks FIRST

Changes:
1. app/api/cluster/status/route.ts:
   - Query exploration database before SSH detection
   - If running chunks exist, mark workers 'active' even if SSH fails
   - Override worker status: 'offline' → 'active' when chunks running
   - Log: '✅ Cluster status: ACTIVE (database shows running chunks)'
   - Database is source of truth, SSH only for supplementary metrics

2. app/cluster/page.tsx:
   - Stop button ALREADY EXISTS (conditionally shown)
   - Shows Start when status='idle', Stop when status='active'
   - No code changes needed - fixed by status detection

Result:
- Dashboard now shows 'ACTIVE' with 2 workers (correct)
- Workers show 'active' status (was 'offline')
- Stop button automatically visible when cluster active
- System resilient to SSH timeouts/network issues

Verified:
- Container restarted: Nov 30 21:18 UTC
- API tested: Returns status='active', activeWorkers=2
- Logs confirm: Database-first logic working
- Workers confirmed running: 22+ processes on worker1, workers on worker2

setup_dual_sweep.sh

@@ -0,0 +1,41 @@
+#!/bin/bash
+# Setup script for dual v9 parameter sweep (vanilla + RSI divergence)
+# Run this on EPYC server after extracting backtest_v9_dual_sweep.tar.gz
+
+set -e
+
+echo "=== v9 Dual Sweep Setup ==="
+echo
+
+# Check Python version
+PYTHON_VERSION=$(python3 --version 2>&1)
+echo "Python: $PYTHON_VERSION"
+
+# Install python3-venv if needed
+if ! dpkg -l | grep -q python3-venv; then
+    echo "Installing python3-venv..."
+    sudo apt-get update
+    sudo apt-get install -y python3-venv
+fi
+
+# Create virtual environment
+if [ ! -d ".venv" ]; then
+    echo "Creating virtual environment..."
+    python3 -m venv .venv
+fi
+
+# Activate and install dependencies
+echo "Installing dependencies..."
+source .venv/bin/activate
+pip install --upgrade pip
+pip install pandas numpy
+
+echo
+echo "=== Setup Complete ==="
+echo "Virtual environment: $(pwd)/.venv"
+echo "Python: $(which python)"
+echo "Packages: $(pip list | grep -E 'pandas|numpy')"
+echo
+echo "Ready to run sweeps!"
+echo "  - Vanilla v9:        ./run_sweep_vanilla_epyc.sh"
+echo "  - RSI Divergence v9: ./run_sweep_rsi_epyc.sh"