feat(prometheus-direct-charting): slice 3 — remove grafana + config rewrite + changelog

Remove the entire Grafana surface: integrations/grafana.py, GrafanaWidgetSource
(+ _fetch_chart, now redundant since prometheus chart exists), GrafanaLinkWidget,
LinksTab, get_grafana_status endpoint, useGrafanaStatus hook, GrafanaStatus type,
fetchGrafanaStatus client fn, registry/nav/tab entries (FE+BE). Rewrite
config.yaml thin-dashboard rule to match reality (recharts is sanctioned for
Prometheus-backed series). CHANGELOG migration note added.

Backend: 293 pytest pass, ruff clean. Frontend: build+lint green (0 errors).
SC-115/116 grep-clean (only prometheus_range.py migration comments + Dashboard.test
shortcut fixture remain — both spec-allowed).

backend/src/media_library_viewer_api/integrations/base.py

@@ -1,7 +1,7 @@
 """Base classes for service integrations.
 
 A *service definition* is a closed, compile-time description of an external service
-the app can talk to (Grafana, Jellyfin, …). Each definition declares:
+the app can talk to (Jellyfin, Prometheus, …). Each definition declares:
 
 * its non-secret ``config_schema`` (derived from a Pydantic model),
 * the secret fields it accepts (API keys / tokens),
@@ -24,7 +24,7 @@ from pydantic import BaseModel, BeforeValidator, Field
 def _validate_service_base_url(value: Any) -> str:
     """Require an absolute http(s) URL for service ``base_url`` fields.
 
-    Relative hosts (e.g. ``grafana.example.com``) break downstream HTTP clients
+    Relative hosts (e.g. ``example.com``) break downstream HTTP clients
     because ``requests`` treats them as relative paths, so we fail fast with a
     clear error instead of letting the call silently malfunction.
     """

backend/src/media_library_viewer_api/integrations/grafana.py

@@ -1,73 +0,0 @@
-"""Grafana service definition."""
-
-from __future__ import annotations
-
-from media_library_viewer_api.integrations.base import (
-    SecretField,
-    ServiceBaseUrl,
-    ServiceConfigBase,
-    ServiceDefinition,
-    WidgetConfigBase,
-    widget_kind,
-)
-
-
-class GrafanaConfig(ServiceConfigBase):
-    """Non-secret Grafana connection config."""
-
-    base_url: ServiceBaseUrl
-    timeout_seconds: int = 5
-
-
-class GrafanaLinkWidgetConfig(WidgetConfigBase):
-    """Deep-link to a Grafana dashboard or panel."""
-
-    dashboard_uid: str
-    panel_id: int | None = None
-
-
-class GrafanaChartWidgetConfig(WidgetConfigBase):
-    """Render a time-series chart from a Grafana datasource query."""
-
-    datasource_uid: str = "prometheus"
-    query: str = ""
-    from_ts: str = "now-1h"
-    to_ts: str = "now"
-    interval_ms: int = 30_000
-    max_data_points: int = 100
-
-
-DEFINITION = ServiceDefinition(
-    service_type="grafana",
-    name="Grafana",
-    description="Dashboards, metrics, and logs.",
-    config_model=GrafanaConfig,
-    secret_fields=[
-        SecretField(key="api_key", label="API key", helper="Service account token (optional)"),
-    ],
-    widget_kinds=[
-        widget_kind(
-            kind="link",
-            name="Dashboard link",
-            description="Deep-link to a Grafana dashboard or panel.",
-            model_cls=GrafanaLinkWidgetConfig,
-            default_config={"dashboard_uid": ""},
-            refresh_interval_ms=0,
-        ),
-        widget_kind(
-            kind="chart",
-            name="Chart",
-            description="Live time-series chart from a Grafana datasource query.",
-            model_cls=GrafanaChartWidgetConfig,
-            default_config={
-                "datasource_uid": "prometheus",
-                "query": "",
-                "from_ts": "now-1h",
-                "to_ts": "now",
-                "interval_ms": 30_000,
-                "max_data_points": 100,
-            },
-            refresh_interval_ms=60_000,
-        ),
-    ],
-)

backend/src/media_library_viewer_api/integrations/registry.py

@@ -10,14 +10,12 @@ from media_library_viewer_api.integrations.alertmanager import DEFINITION as ALE
 from media_library_viewer_api.integrations.authentik import DEFINITION as AUTHENTIK
 from media_library_viewer_api.integrations.backups import DEFINITION as BACKUPS
 from media_library_viewer_api.integrations.base import ServiceDefinition, WidgetKind
-from media_library_viewer_api.integrations.grafana import DEFINITION as GRAFANA
 from media_library_viewer_api.integrations.jellyfin import DEFINITION as JELLYFIN
 from media_library_viewer_api.integrations.nextcloud import DEFINITION as NEXTCLOUD
 from media_library_viewer_api.integrations.prometheus import DEFINITION as PROMETHEUS
 from media_library_viewer_api.integrations.ssh_tasks import DEFINITION as SSH_TASKS
 
 SERVICE_DEFINITIONS: dict[str, ServiceDefinition] = {
-    GRAFANA.service_type: GRAFANA,
     PROMETHEUS.service_type: PROMETHEUS,
     ALERTMANAGER.service_type: ALERTMANAGER,
     JELLYFIN.service_type: JELLYFIN,