Initial commit: Sentry-Emote system monitor

- Aggregator: Flask-based event broker with priority queue
- Frontend: OLED-optimized UI with animations
- Detectors: disk, cpu, memory, service, network
- Unified entry point (sentry.py) with process management
- Heartbeat TTL system for auto-clearing stale events

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

CLAUDE.md

@@ -0,0 +1,121 @@
+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Project Overview
+
+Sentry-Emote is a minimalist system status monitor designed for an old Pixel phone used as an ambient display. It uses ASCII "emotes" to represent system health instead of complex graphs.
+
+## Architecture
+
+**Publisher/Subscriber model:**
+
+```
+┌─────────────┐     POST /event      ┌─────────────┐     GET /status     ┌─────────────┐
+│  Detectors  │ ──────────────────▶  │  Aggregator │ ◀────────────────── │   Emote-UI  │
+│  (sensors)  │                      │   (broker)  │                     │  (display)  │
+└─────────────┘                      └─────────────┘                     └─────────────┘
+```
+
+- **Aggregator** (`aggregator.py`) — Flask service managing the event queue and priority logic
+- **Detectors** (`detectors/*.py`) — Independent scripts monitoring system metrics
+- **Emote-UI** (`index.html`) — OLED-optimized web frontend
+- **Sentry** (`sentry.py`) — Unified entry point managing all processes
+
+## Quick Start
+
+```bash
+# Setup
+python -m venv venv
+source venv/bin/activate  # or .\venv\Scripts\activate on Windows
+pip install -r requirements.txt
+
+# Run everything
+python sentry.py
+```
+
+UI available at http://localhost:5000
+
+## Configuration
+
+Edit `config.json` to configure the aggregator URL, enable/disable detectors, and set thresholds.
+
+```json
+{
+  "aggregator_url": "http://localhost:5000",
+  "aggregator": { "script": "aggregator.py" },
+  "detectors": [
+    {
+      "name": "cpu",
+      "enabled": true,
+      "script": "detectors/cpu.py",
+      "env": {
+        "CHECK_INTERVAL": "30",
+        "THRESHOLD_WARNING": "85",
+        "THRESHOLD_CRITICAL": "95"
+      }
+    }
+  ]
+}
+```
+
+## Detectors
+
+| Detector | Script | Required Env Vars |
+|----------|--------|-------------------|
+| Disk Space | `detectors/disk_space.py` | — |
+| CPU | `detectors/cpu.py` | — |
+| Memory | `detectors/memory.py` | — |
+| Service | `detectors/service.py` | `SERVICES` (comma-separated process names) |
+| Network | `detectors/network.py` | `HOSTS` (comma-separated hostnames/IPs) |
+
+All detectors support: `AGGREGATOR_URL`, `CHECK_INTERVAL`, `THRESHOLD_WARNING`, `THRESHOLD_CRITICAL`
+
+## API Endpoints
+
+- `POST /event` — Register event: `{"id": "name", "priority": 1-4, "message": "optional", "ttl": optional_seconds}`
+- `POST /clear` — Clear event: `{"id": "name"}`
+- `GET /status` — Current state JSON
+- `GET /events` — List active events
+
+## Priority System
+
+Lower number = higher priority. Events with a `ttl` auto-expire (heartbeat pattern).
+
+| Priority | State    | Emote    | Color  | Behavior |
+|----------|----------|----------|--------|----------|
+| 1 | Critical | `( x_x)` | Red | Shaking animation |
+| 2 | Warning | `( o_o)` | Yellow | Breathing animation |
+| 3 | Notify | `( 'o')` | Blue | Popping animation, 10s default TTL |
+| 4 | Optimal | `( ^_^)` | Green | Default when no events |
+
+## Testing Events
+
+```bash
+# Warning with 30s TTL
+curl -X POST -H "Content-Type: application/json" \
+  -d '{"id":"test","priority":2,"message":"Test warning","ttl":30}' \
+  http://localhost:5000/event
+
+# Clear manually
+curl -X POST -H "Content-Type: application/json" \
+  -d '{"id":"test"}' \
+  http://localhost:5000/clear
+```
+
+## File Structure
+
+```
+├── sentry.py           # Unified entry point
+├── aggregator.py       # Event broker/API server
+├── index.html          # OLED-optimized frontend
+├── config.json         # Runtime configuration
+├── detectors/
+│   ├── disk_space.py
+│   ├── cpu.py
+│   ├── memory.py
+│   ├── service.py
+│   └── network.py
+├── requirements.txt
+└── SPEC.md             # Original project specification
+```