feat: add system stats API for dashboard monitoring

- GET /tools/system/stats - Real-time host system statistics
- CPU usage, memory, all mounted disks, network I/O
- GPU/VRAM stats via nvidia-smi (if available)
- Uses psutil for cross-platform host metrics
- Auto-discovers and filters real filesystems

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

CHANGELOG.md

@@ -5,6 +5,19 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [1.7.0] - 2026-01-03
+
+### Added
+
+- **System Stats API** - Host system resource monitoring for dashboard widgets
+  - `GET /tools/system/stats` - Real-time host system statistics
+  - CPU: usage percentage, core count, load averages
+  - Memory: usage percentage, total/used/available bytes
+  - Disks: all mounted filesystems with usage stats (auto-discovers mounts)
+  - Network: total bytes sent/received
+  - GPU/VRAM: NVIDIA GPU memory usage (via nvidia-smi if available)
+- `psutil` dependency for cross-platform system metrics
+
 ## [1.6.1] - 2026-01-03
 
 ### Added