v0.5.0 - Wake-on-LAN + connectivity history

wol.py:
- build_magic_packet(): standard 6x0xFF + 16x MAC layout
- send_local_broadcast(): direct from container (ports 9 + 7 for safety)
- send_via_peer(): preferred path; SSHes to the OTHER Spark and runs a Python one-liner there so the packet originates on the target's LAN segment (most reliable)
- MAC validation + normalization

connectivity.py:
- /data/connectivity.json persistence (thread-safe, atomic rename)
- Stores per-Spark current state + last_change timestamp + rolling 200-event log
- Records up/down transitions; computes down_seconds / up_seconds durations
- MAC cache populated lazily during hardware probes

hardware.py:
- Probe now reads MAC via /sys/class/net/<default-route-iface>/address
- After each probe, record_state() emits a transition event if state changed
- record_mac() caches the address so WoL works when the Spark next goes down

Endpoints:
- GET /api/connectivity: macs, current state, last_change, events[]
- POST /api/spark/{name}/wake: tries via-peer first, falls back to direct broadcast

UI:
- Unreachable hardware card shows the cached MAC + 'Wake (WoL)' button (only if MAC known)
- New 'Connectivity log' button opens a modal with per-Spark transition history (last 25 each), including duration of each prior up/down period
- pollHardware also pulls /api/connectivity so WoL buttons appear without an extra fetch

Package: bump 0.5.0:0; main.ts sets CONNECTIVITY_LOG=/data/connectivity.json

package/startos/main.ts

@@ -50,6 +50,7 @@ export const main = sdk.setupMain(async ({ effects }) => {
         MAGPIE_CONTAINER: cfg.magpie_container,
         MODELS_OVERRIDES: '/data/models-overrides.yaml',
         SERVICES_OVERRIDES: '/data/services-overrides.yaml',
+        CONNECTIVITY_LOG: '/data/connectivity.json',
         OPEN_WEBUI_URL: cfg.open_webui_url,
         NGC_API_KEY: cfg.ngc_api_key,
         BIND_PORT: String(uiPort),