Add read-only web dashboard and phone push notifications

Both zero-dependency (stdlib http.server + urllib), consistent with the
project's no-dependency-tree stance for a security daemon.

Web dashboard (enodia_sentinel/web.py + static/dashboard.html):
- read-only JSON API over the log dir: /api/status, /api/alerts,
  /api/alerts/<id>, /api/events
- bearer-token auth (constant-time; header or ?token=), required on non-
  loopback binds, auto-generated + persisted (0600) when unset
- binds the host's Tailscale IP by default (auto-detected), reachable from the
  tailnet but not the LAN/internet
- self-contained dark SPA: severity cards, live alert list, full snapshot
  viewer; 10s auto-refresh
- path-traversal-safe alert lookup; `enodia-sentinel web` subcommand; daemon
  now writes a pidfile so the dashboard can show live status
- hardened enodia-sentinel-web.service (read-only, no caps)

Phone push (enodia_sentinel/notify/):
- pluggable backends — ntfy, Pushover, generic webhook — each separating a pure
  build() (unit-tested, no network) from send()
- a backend turns on when its config keys are set; pushes gated by
  notify_min_severity; severity → per-service priority/tags
- fired from snapshot.capture on worker threads, errors swallowed
- desktop notify-send retained

Tests: +16 (9 web incl. a real-server 401/200 auth test, 7 notify request-build
cases). 55/55 pass. Live end-to-end verified: daemon → alert → API → page.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

tests/test_web.py

@@ -0,0 +1,126 @@
+# SPDX-License-Identifier: GPL-3.0-or-later
+"""Tests for the read-only web dashboard: data layer + auth (real server)."""
+import json
+import tempfile
+import threading
+import unittest
+import urllib.error
+import urllib.request
+from pathlib import Path
+
+from enodia_sentinel import web
+from enodia_sentinel.config import Config
+
+
+def _make_cfg(tmp: Path) -> Config:
+    c = Config()
+    c.log_dir = tmp
+    return c
+
+
+def _write_alert(tmp: Path, name: str, severity: str, sigs):
+    alerts = [{"signature": s, "sid": 100010, "severity": severity} for s in sigs]
+    (tmp / f"{name}.json").write_text(json.dumps({
+        "time": "2026-05-31T00:00:00-07:00", "host": "woofbox",
+        "severity": severity, "alerts": alerts,
+    }))
+    (tmp / f"{name}.log").write_text(f"=== ENODIA SENTINEL ALERT ===\n{severity}\n")
+
+
+class TestDataLayer(unittest.TestCase):
+    def setUp(self):
+        self.dir = tempfile.TemporaryDirectory()
+        self.tmp = Path(self.dir.name)
+        self.cfg = _make_cfg(self.tmp)
+
+    def tearDown(self):
+        self.dir.cleanup()
+
+    def test_list_and_status(self):
+        _write_alert(self.tmp, "alert-20260531-000001", "CRITICAL", ["reverse_shell"])
+        _write_alert(self.tmp, "alert-20260531-000002", "HIGH", ["new_listener"])
+        alerts = web.list_alerts(self.cfg)
+        self.assertEqual(len(alerts), 2)
+        self.assertEqual(alerts[0]["name"], "alert-20260531-000002.log")  # newest first
+        st = web.daemon_status(self.cfg)
+        self.assertEqual(st["total_alerts"], 2)
+        self.assertEqual(st["counts"]["CRITICAL"], 1)
+        self.assertFalse(st["running"])  # no live pidfile
+
+    def test_get_alert_and_traversal(self):
+        _write_alert(self.tmp, "alert-20260531-000001", "CRITICAL", ["x"])
+        got = web.get_alert(self.cfg, "alert-20260531-000001.log")
+        self.assertIn("text", got)
+        self.assertIn("json", got)
+        # path traversal / bad names rejected
+        self.assertIsNone(web.get_alert(self.cfg, "../../etc/passwd"))
+        self.assertIsNone(web.get_alert(self.cfg, "events.log"))
+
+    def test_tail_events(self):
+        (self.tmp / "events.log").write_text("l1\nl2\nl3\n")
+        self.assertEqual(web.tail_events(self.cfg, 2), ["l2", "l3"])
+
+
+class TestNetworkHelpers(unittest.TestCase):
+    def test_is_loopback(self):
+        self.assertTrue(web.is_loopback("127.0.0.1"))
+        self.assertFalse(web.is_loopback("100.64.1.2"))
+
+    def test_resolve_bind_explicit(self):
+        c = Config()
+        c.web_bind = "100.64.1.2"
+        self.assertEqual(web.resolve_bind(c), "100.64.1.2")
+
+    def test_ensure_token_persists(self):
+        with tempfile.TemporaryDirectory() as d:
+            c = _make_cfg(Path(d))
+            t1 = web.ensure_token(c)
+            t2 = web.ensure_token(c)
+            self.assertTrue(t1)
+            self.assertEqual(t1, t2)  # stable across calls
+
+
+class TestAuth(unittest.TestCase):
+    """Spin up the real server on loopback and check token enforcement."""
+
+    def setUp(self):
+        self.dir = tempfile.TemporaryDirectory()
+        self.tmp = Path(self.dir.name)
+        _write_alert(self.tmp, "alert-20260531-000001", "CRITICAL", ["reverse_shell"])
+        self.cfg = _make_cfg(self.tmp)
+        self.cfg.web_bind = "127.0.0.1"
+        self.cfg.web_port = 0          # ephemeral
+        self.cfg.web_token = "secret-token"
+        self.httpd, _bind, _tok = web.build_server(self.cfg)
+        self.port = self.httpd.server_address[1]
+        self.t = threading.Thread(target=self.httpd.serve_forever, daemon=True)
+        self.t.start()
+
+    def tearDown(self):
+        self.httpd.shutdown()
+        self.dir.cleanup()
+
+    def _get(self, path, token=None):
+        url = f"http://127.0.0.1:{self.port}{path}"
+        req = urllib.request.Request(url)
+        if token:
+            req.add_header("Authorization", f"Bearer {token}")
+        return urllib.request.urlopen(req, timeout=4)
+
+    def test_unauthorized_without_token(self):
+        with self.assertRaises(urllib.error.HTTPError) as cm:
+            self._get("/api/status")
+        self.assertEqual(cm.exception.code, 401)
+
+    def test_authorized_with_token(self):
+        resp = self._get("/api/status", token="secret-token")
+        data = json.loads(resp.read())
+        self.assertEqual(data["total_alerts"], 1)
+
+    def test_token_via_query_param(self):
+        resp = self._get("/api/alerts?token=secret-token")
+        self.assertEqual(resp.status, 200)
+
+
+if __name__ == "__main__":
+    unittest.main()