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

image/app/connectivity.py

@@ -0,0 +1,126 @@
+"""Track Spark up/down transitions and cache discovered MAC addresses.
+
+Persisted to /data/connectivity.json so history survives package restarts:
+
+    {
+      "macs": { "spark1": "aa:bb:..", "spark2": "11:22:.." },
+      "current": { "spark1": "up", "spark2": "down" },
+      "last_change": { "spark1": "2026-05-12T15:00:00Z", ... },
+      "events": [
+        { "spark": "spark2", "at": "2026-05-12T17:30:00Z", "transition": "down" },
+        { "spark": "spark2", "at": "2026-05-12T18:45:00Z", "transition": "up", "down_seconds": 4500 },
+        ...
+      ]
+    }
+"""
+from __future__ import annotations
+import json
+import os
+import threading
+from datetime import datetime, timezone
+from pathlib import Path
+from typing import Optional
+
+
+MAX_EVENTS = 200  # rolling window — plenty for showing recent history
+
+
+def _path() -> str:
+    return os.environ.get("CONNECTIVITY_LOG", "/data/connectivity.json")
+
+
+_lock = threading.Lock()
+
+
+def _read() -> dict:
+    try:
+        with open(_path()) as f:
+            return json.load(f) or {}
+    except (FileNotFoundError, json.JSONDecodeError):
+        return {}
+
+
+def _write(data: dict) -> None:
+    p = _path()
+    Path(p).parent.mkdir(parents=True, exist_ok=True)
+    tmp = p + ".tmp"
+    with open(tmp, "w") as f:
+        json.dump(data, f, indent=2, sort_keys=False)
+    os.replace(tmp, p)
+
+
+def load() -> dict:
+    with _lock:
+        d = _read()
+        d.setdefault("macs", {})
+        d.setdefault("current", {})
+        d.setdefault("last_change", {})
+        d.setdefault("events", [])
+        return d
+
+
+def record_mac(spark: str, mac: Optional[str]) -> None:
+    if not mac:
+        return
+    with _lock:
+        d = _read()
+        d.setdefault("macs", {})
+        if d["macs"].get(spark) != mac:
+            d["macs"][spark] = mac
+            _write(d)
+
+
+def record_state(spark: str, reachable: bool) -> Optional[dict]:
+    """Update current state. If it differs from the last seen state, append an event.
+
+    Returns the event dict if a transition was recorded, else None.
+    """
+    new_state = "up" if reachable else "down"
+    now = datetime.now(timezone.utc).isoformat().replace("+00:00", "Z")
+    with _lock:
+        d = _read()
+        d.setdefault("macs", {})
+        d.setdefault("current", {})
+        d.setdefault("last_change", {})
+        d.setdefault("events", [])
+        prev = d["current"].get(spark)
+        if prev == new_state:
+            return None
+        event: dict = {"spark": spark, "at": now, "transition": new_state}
+        # When we have a previous state and timestamp, compute duration
+        last_change = d["last_change"].get(spark)
+        if prev and last_change:
+            try:
+                prev_dt = datetime.fromisoformat(last_change.replace("Z", "+00:00"))
+                duration = (datetime.now(timezone.utc) - prev_dt).total_seconds()
+                if prev == "down" and new_state == "up":
+                    event["down_seconds"] = round(duration)
+                if prev == "up" and new_state == "down":
+                    event["up_seconds"] = round(duration)
+            except ValueError:
+                pass
+        d["current"][spark] = new_state
+        d["last_change"][spark] = now
+        d["events"].append(event)
+        # Keep rolling window
+        if len(d["events"]) > MAX_EVENTS:
+            d["events"] = d["events"][-MAX_EVENTS:]
+        _write(d)
+        return event
+
+
+def get_mac(spark: str) -> Optional[str]:
+    d = load()
+    return d.get("macs", {}).get(spark)
+
+
+def summary() -> dict:
+    """Compact summary for the UI: known MACs, current state, recent events."""
+    d = load()
+    events = d.get("events", [])
+    return {
+        "macs": d.get("macs", {}),
+        "current": d.get("current", {}),
+        "last_change": d.get("last_change", {}),
+        "events": events[-50:],
+    }