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>

fabledscryer/core/plugin_index.py

@@ -0,0 +1,77 @@
+# fabledscryer/core/plugin_index.py
+"""Remote plugin catalog: fetch, parse, and cache the plugin index.yaml."""
+from __future__ import annotations
+import logging
+import time
+from typing import Any
+
+logger = logging.getLogger(__name__)
+
+_CACHE_TTL = 300  # seconds
+_cache: tuple[dict, float] | None = None  # (raw_data, fetched_at monotonic)
+
+
+class CatalogPlugin:
+    """One entry from the remote plugin index."""
+
+    __slots__ = (
+        "name", "version", "description", "author",
+        "min_app_version", "download_url", "checksum_sha256",
+        "repository_url", "homepage", "license", "tags",
+    )
+
+    def __init__(self, data: dict[str, Any]) -> None:
+        self.name: str = data.get("name", "")
+        self.version: str = data.get("version", "0.0.0")
+        self.description: str = data.get("description", "")
+        self.author: str = data.get("author", "")
+        self.min_app_version: str | None = data.get("min_app_version")
+        self.download_url: str = data.get("download_url", "")
+        self.checksum_sha256: str = data.get("checksum_sha256", "")
+        self.repository_url: str = data.get("repository_url", "")
+        self.homepage: str = data.get("homepage", "")
+        self.license: str = data.get("license", "")
+        self.tags: list[str] = data.get("tags", [])
+
+
+async def fetch_catalog(index_url: str, force: bool = False) -> list[CatalogPlugin]:
+    """Fetch and parse the remote plugin catalog.
+
+    Results are cached in-process for _CACHE_TTL seconds. Pass force=True to
+    bypass the cache. On network failure, stale cached data is returned if
+    available; otherwise an empty list is returned.
+    """
+    global _cache
+    import httpx
+    import yaml
+
+    now = time.monotonic()
+    if not force and _cache is not None:
+        raw, fetched_at = _cache
+        if now - fetched_at < _CACHE_TTL:
+            return [CatalogPlugin(p) for p in raw.get("plugins", [])]
+
+    try:
+        async with httpx.AsyncClient(timeout=10) as client:
+            resp = await client.get(index_url)
+            resp.raise_for_status()
+        raw = yaml.safe_load(resp.text) or {}
+        _cache = (raw, now)
+        logger.info(
+            "Plugin catalog fetched from %s: %d plugin(s)",
+            index_url, len(raw.get("plugins", [])),
+        )
+        return [CatalogPlugin(p) for p in raw.get("plugins", [])]
+    except Exception:
+        logger.exception("Failed to fetch plugin catalog from %s", index_url)
+        if _cache is not None:
+            raw, _ = _cache
+            logger.warning("Returning stale cached catalog")
+            return [CatalogPlugin(p) for p in raw.get("plugins", [])]
+        return []
+
+
+def clear_catalog_cache() -> None:
+    """Invalidate the in-process catalog cache."""
+    global _cache
+    _cache = None