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>

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "enodia-sentinel"
-version = "0.3.0"
+version = "0.4.0"
 description = "Host intrusion-detection daemon — signature-based detection of reverse shells, LD_PRELOAD rootkits, fileless malware, and persistence tampering"
 readme = "README.md"
 requires-python = ">=3.11"
@@ -29,3 +29,6 @@ dev = ["pytest"]
 
 [tool.setuptools.packages.find]
 include = ["enodia_sentinel*"]
+
+[tool.setuptools.package-data]
+enodia_sentinel = ["static/*.html"]