Add parallel capacity test tool for Hermes/OpenCode

This tool tests the practical limits of parallel agent execution
by spawning N concurrent opencode run tasks and measuring:
- Response time
- CPU and memory usage
- Success/failure rates

Includes both bash (run_test.sh) and Python (parallel_capacity_test.py)
implementations with full metrics collection and reporting.

Fixes #3

tools/parallel-capacity-test/README.md

@@ -0,0 +1,74 @@
+# Parallel Capacity Test Tool
+
+Tests the practical limits of parallel agent execution for Hermes/OpenCode.
+
+## Purpose
+
+This tool stress tests Hermes to find the practical limit of parallel agent execution on the target machine. It:
+
+- Spawns N concurrent `opencode run` agents
+- Measures CPU, memory, and response time
+- Ramps up from 1 to higher agent counts
+- Identifies failure points and performance degradation
+
+## Files
+
+- `run_test.sh` - Bash script for running tests
+- `parallel_capacity_test.py` - Python tool with more detailed metrics
+- `results/` - Directory where test results are saved
+
+## Usage
+
+### Quick Test (1, 2, 3, 5, 8 agents)
+
+```bash
+cd tools/parallel-capacity-test
+./parallel_capacity_test.py --quick
+```
+
+### Full Test Suite
+
+```bash
+./parallel_capacity_test.py --agents 15 --timeout 120
+```
+
+### Bash Script Usage
+
+```bash
+./run_test.sh quick    # Quick test
+./run_test.sh full     # Full test up to MAX_AGENTS
+```
+
+## Environment Variables
+
+| Variable | Default | Description |
+|----------|---------|-------------|
+| MAX_AGENTS | 15 | Maximum number of agents to test |
+| STEP | 1 | Step size for agent increment |
+| TASK_TIMEOUT | 120 | Timeout for each agent task |
+
+## Metrics Collected
+
+- **Response Time** - Time from agent launch to completion
+- **CPU Usage** - System-wide CPU utilization percentage
+- **Memory Usage** - System-wide memory utilization percentage
+- **Success Rate** - Percentage of agents completing successfully
+- **Process Count** - Number of opencode processes running
+
+## Expected Behavior
+
+Based on the Hermes architecture:
+
+| Agent Count | Expected Performance |
+|-------------|---------------------|
+| 1-3 | Optimal - safe for production |
+| 4-6 | Good - monitor closely |
+| 7-10 | Degraded - not recommended |
+| 10+ | Poor - avoid without significant resources |
+
+## Output Files
+
+- `results_YYYYMMDD_HHMMSS.json` - Complete raw results
+- `summary_YYYYMMDD_HHMMSS.csv` - CSV summary of metrics
+- `report_YYYYMMDD_HHMMSS.md` - Markdown analysis report
+EOF; __hermes_rc=$?; printf '__HERMES_FENCE_a9f7b3__'; exit $__hermes_rc