feat: v0.1.4 — device intelligence dashboard

Add tabbed dashboard at /dashboard/ with three D3.js visualizations:
- Vendor treemap (devices grouped by type and vendor)
- SSID social graph (force-directed, shared probed SSIDs as edges)
- Fingerprint clusters (packed circles by device behavior)

Intelligence API endpoints at /api/v1/intelligence/ with param
validation. Dashboard built on htmx + Pico CSS dark theme + D3 v7,
all vendored locally (make vendor). 13 new tests (59 total).

docs/CHEATSHEET.md

@@ -27,6 +27,12 @@ pytest -v       # Verbose output
 pytest -k test_sensors  # Run specific tests
 ```
 
+## Static Assets
+
+```bash
+make vendor     # Download Pico CSS, htmx, D3.js to static/vendor/
+```
+
 ## Container
 
 ```bash
@@ -66,6 +72,14 @@ curl localhost:5500/api/v1/probes/ssids
 
 # Stats
 curl localhost:5500/api/v1/stats
+
+# Intelligence (Device Intelligence Dashboard)
+curl localhost:5500/api/v1/intelligence/vendor-treemap
+curl "localhost:5500/api/v1/intelligence/ssid-graph?hours=24&min_shared=1&limit=200"
+curl "localhost:5500/api/v1/intelligence/fingerprint-clusters?hours=24"
+
+# Dashboard
+open http://localhost:5500/dashboard/
 ```
 
 ## Query Parameters
@@ -78,6 +92,8 @@ curl localhost:5500/api/v1/stats
 | offset | devices, alerts, events, probes | Skip N results |
 | ssid | probes | Filter by SSID |
 | sensor_id | alerts, events | Filter by sensor |
+| hours | intelligence/ssid-graph, intelligence/fingerprint-clusters | Time window (default: 24) |
+| min_shared | intelligence/ssid-graph | Min shared SSIDs for link (default: 1) |
 
 ## Files