Make service connection config editable on service page

The service detail page showed non-secret connection config (base_url,
user_id, username, timeout_seconds) as read-only. Render schema-driven
editable inputs (reusing the create-dialog pattern) with a draftConfig
state hydrated from the instance, and unify the save button to persist
both config and secrets. Number fields render as type=number; the base_url
schema description surfaces as helper text.

backend/src/media_library_viewer_api/integrations/.pi-map.index.md

@@ -2,7 +2,7 @@
 dir: backend/src/media_library_viewer_api/integrations
 
 ## role
-Defines and registers third-party service integrations (e.g., Alertmanager, Grafana, Jellyfin, Prometheus) with typed configs, secrets, and widget definitions for the media library viewer API.
+Provides a plugin-style integration framework for declaring and registering external service connections (e.g., Grafana, Jellyfin, Prometheus) with config schemas, secrets, and widget definitions for the media library viewer API.
 ## parent
 index: backend/src/media_library_viewer_api/.pi-map.index.md
 map: backend/src/media_library_viewer_api/.pi-map.md

backend/src/media_library_viewer_api/integrations/.pi-map.md

@@ -4,22 +4,22 @@ dir: backend/src/media_library_viewer_api/integrations
 index: backend/src/media_library_viewer_api/integrations/.pi-map.index.md
 
 ## role
-Defines and registers third-party service integrations (e.g., Alertmanager, Grafana, Jellyfin, Prometheus) with typed configs, secrets, and widget definitions for the media library viewer API.
+Provides a plugin-style integration framework for declaring and registering external service connections (e.g., Grafana, Jellyfin, Prometheus) with config schemas, secrets, and widget definitions for the media library viewer API.
 ## files
 - __init__.py | Defines a closed registry module for service integrations.
-- alertmanager.py | Defines the Alertmanager service integration, including connection config, widget definitions, and alert summarization logic. | exp: class:AlertmanagerConfig, class:AlertmanagerAlertsWidgetConfig, func:summarize_alerts(alerts: list[dict[str, Any]], severity_filter) → dict[str, Any], call:alert.get, call:labels.get, call:by_severity.get, call:open_alerts.append, call:annotations.get, call:open_alerts.sort, call:len | dep: typing, media_library_viewer_api.integrations.base
-- base.py | Defines base classes and utilities for creating compile-time service integration definitions with Pydantic-based config schemas, secret fields, and widget kinds. | exp: class:ServiceConfigBase, class:WidgetConfigBase, class:SecretField, class:WidgetKind, class:ServiceDefinition, method:widget_kind(self, kind: str) → WidgetKind | None, func:widget_kind(kind: str, name: str, description: str, model_cls: type[WidgetConfigBase], default_config, refresh_interval_ms) → WidgetKind, call:model_cls.model_json_schema, call:schema.pop, call:WidgetKind, call:dict, func:validate_config(model_cls: type[BaseModel], config: dict[str, Any] | None) → dict[str, Any], call:model_cls.model_validate, call:instance.model_dump | dep: dataclasses, typing, pydantic
-- grafana.py | Defines the Grafana service configuration, secret fields, and widget types for integration with the media library viewer API. | exp: class:GrafanaConfig, class:GrafanaLinkWidgetConfig | dep: media_library_viewer_api.integrations.base
-- jellyfin.py | Defines the Jellyfin media server service configuration and activity widget definition for a media library viewer API. | exp: class:JellyfinConfig, class:JellyfinActivityWidgetConfig | dep: media_library_viewer_api.integrations.base
-- jellyseerr.py | Defines a service configuration and metadata for Jellyseerr, a request management companion to Jellyfin. | exp: class:JellyseerrConfig | dep: media_library_viewer_api.integrations.base
+- alertmanager.py | Defines the Alertmanager service integration configuration, widget definitions, and alert summarization logic for a media library viewer API. | exp: class:AlertmanagerConfig, class:AlertmanagerAlertsWidgetConfig, func:summarize_alerts(alerts: list[dict[str, Any]], severity_filter) → dict[str, Any], call:alert.get, call:labels.get, call:by_severity.get, call:open_alerts.append, call:annotations.get, call:open_alerts.sort, call:len | dep: typing, media_library_viewer_api.integrations.base
+- base.py | Provides abstract base classes and dataclass definitions for declaring external service integrations with config schemas, secret fields, and widget kinds. | exp: class:ServiceConfigBase, class:WidgetConfigBase, class:SecretField, class:WidgetKind, class:ServiceDefinition, method:widget_kind(self, kind: str) → WidgetKind | None, func:_validate_service_base_url(value: Any) → str, call:isinstance, call:value.strip, call:text.lower, call:lowered.startswith, raise:ValueError, func:widget_kind(kind: str, name: str, description: str, model_cls: type[WidgetConfigBase], default_config, refresh_interval_ms) → WidgetKind, call:model_cls.model_json_schema, call:schema.pop, call:WidgetKind, call:dict, func:validate_config(model_cls: type[BaseModel], config: dict[str, Any] | None) → dict[str, Any], call:model_cls.model_validate, call:instance.model_dump | dep: dataclasses, typing, pydantic
+- grafana.py | Defines the Grafana service integration configuration, including connection settings, API key secrets, and dashboard link widget support. | exp: class:GrafanaConfig, class:GrafanaLinkWidgetConfig | dep: media_library_viewer_api.integrations.base
+- jellyfin.py | Defines the Jellyfin service configuration and activity widget for a media library viewer API integration. | exp: class:JellyfinConfig, class:JellyfinActivityWidgetConfig | dep: media_library_viewer_api.integrations.base
+- jellyseerr.py | Defines the Jellyseerr service configuration and its service definition schema for integration as a request management companion to Jellyfin. | exp: class:JellyseerrConfig | dep: media_library_viewer_api.integrations.base
 - nextcloud.py | Defines the Nextcloud service configuration model and service definition for integration into the media library viewer API. | exp: class:NextcloudConfig | dep: media_library_viewer_api.integrations.base
-- prometheus.py | Defines the service configuration, widget types, and service definition for integrating Prometheus as a metrics data source. | exp: class:PrometheusConfig, class:PrometheusMetricWidgetConfig | dep: media_library_viewer_api.integrations.base
+- prometheus.py | Defines the service definition and configuration models for integrating Prometheus as a metrics data source with PromQL query widgets. | exp: class:PrometheusConfig, class:PrometheusMetricWidgetConfig | dep: media_library_viewer_api.integrations.base
 - registry.py | Provides a closed registry of service definitions with lookup and enumeration functions. | exp: func:list_service_types() → list[str], call:sorted, func:get_service_definition(service_type: str) → ServiceDefinition | None, call:SERVICE_DEFINITIONS.get, func:get_widget_kind(service_type: str, widget_kind: str) → WidgetKind | None, call:get_service_definition, call:definition.widget_kind, func:require_service_definition(service_type: str) → ServiceDefinition, call:get_service_definition, raise:ValueError | dep: media_library_viewer_api.integrations.alertmanager, media_library_viewer_api.integrations.base, media_library_viewer_api.integrations.grafana, media_library_viewer_api.integrations.jellyfin, media_library_viewer_api.integrations.jellyseerr, media_library_viewer_api.integrations.nextcloud, media_library_viewer_api.integrations.prometheus, media_library_viewer_api.integrations.ssh_tasks
 - ssh_tasks.py | Defines a service configuration for an SSH task runner that executes reusable saved tasks over SSH and records run history. | exp: class:SshTasksConfig, class:SshTaskOutputWidgetConfig | dep: media_library_viewer_api.integrations.base
 ## arch
-Plugin/registry pattern using Pydantic-based config schemas with a closed registry for compile-time service definition lookups, base class extension for per-service widgets and secrets, and a modular file-per-integration structure.
+Registry pattern with abstract base classes and dataclass-driven configuration models; each integration is a self-contained module registered in a closed registry that supports lookup, enumeration, and declarative widget/kind definitions.
 ## tags
-config, service, widget, integrations, media_library_viewer_api, base, definition, kind
+config, service, widget, integrations, base, media_library_viewer_api, definition, kind
 ## symbols
 - AlertmanagerConfig
 - AlertmanagerAlertsWidgetConfig