feat: rename to FabledScryer, multi-dashboard system, plugin management, branding

- Rename package fablednetmon → fabledscryer throughout
- Multi-dashboard: ownership, per-user defaults, HTMX edit (add/remove/reorder)
- Read-only share tokens scoped to individual dashboards
- Dashboard edit is HTMX-driven (no page reloads)
- Plugin management system: remote catalog, download/install, hot-reload, in-app restart
- plugin_index.py: fetch/cache remote index.yaml; default URL → bvandeusen/fabledscryer-plugins
- plugin_manager.py: download_and_install_plugin, hot_reload_plugin, restart_app
  - ZIP extraction handles GitHub archive formats (name-v1.0.0/, name-main/)
- Settings split into tabbed sections: General, Notifications, Ansible, Plugins
- Plugins tab: catalog browser (HTMX), install/activate/update/restart actions
- UI/branding: dark palette (#07071a), crystal ball SVG logo, animated star field,
  Libertinus Serif applied to headings, nav, labels, and section titles
- Widget registry (core/widgets.py) for dashboard plugin integration
- UPS widget.html (dashboard card) and settings/_tabs.html include
- Migrations 0005–0008: dashboards, is_default, ownership, share tokens
- docs/plugins/: writing-a-plugin.md updated with publishing guide,
  index.yaml.example template for fabledscryer-plugins repo

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Dockerfile

@@ -1,4 +1,4 @@
-FROM python:3.11-slim
+FROM python:3.13-slim
 
 RUN DEBIAN_FRONTEND=noninteractive apt-get update \
     && DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends iputils-ping \
@@ -10,7 +10,7 @@ RUN pip install --upgrade pip
 WORKDIR /app
 
 COPY pyproject.toml .
-COPY fablednetmon/ fablednetmon/
+COPY fabledscryer/ fabledscryer/
 RUN pip install --no-cache-dir .
 
 COPY alembic.ini .
@@ -24,4 +24,4 @@ USER app
 
 EXPOSE 5000
 
-CMD ["fablednetmon", "--host", "0.0.0.0", "--port", "5000"]
+CMD ["fabledscryer", "--host", "0.0.0.0", "--port", "5000"]