feat(FN-3079): add plugin dashboard views and dependency graph plugin

- Add plugin dashboard view registration and hosting across core, dashboard routes, and plugin SDK exports
- Integrate plugin-provided views into app navigation, mobile/header UI, and view state hooks with coverage
- Add fusion-plugin-dependency-graph example plugin with persisted storage, dashboard view UI, and manifest wiring
- Update plugin authoring and architecture docs for dashboard view extension points
- Add a changeset for @runfusion/fusion covering plugin dashboard view support

Fusion-Task-Id: FN-3079

packages/dashboard/app/api/legacy.ts

@@ -19,6 +19,7 @@ import type {
   WorkflowStepResult,
   PluginInstallation,
   PluginUiSlotDefinition,
+  PluginDashboardViewDefinition,
   TaskDocument,
   TaskDocumentRevision,
   TaskDocumentWithTask,
@@ -7478,6 +7479,12 @@ export interface PluginUiSlotEntry {
   slot: PluginUiSlotDefinition;
 }
 
+/** A dashboard view entry returned by GET /api/plugins/dashboard-views */
+export interface PluginDashboardViewEntry {
+  pluginId: string;
+  view: PluginDashboardViewDefinition;
+}
+
 /** Plugin runtime metadata returned by GET /api/plugins/runtimes */
 export interface PluginRuntimeInfo {
   pluginId: string;
@@ -7492,6 +7499,12 @@ export async function fetchPluginUiSlots(projectId?: string): Promise<PluginUiSl
   return api<PluginUiSlotEntry[]>(withProjectId("/plugins/ui-slots", projectId));
 }
 
+
+/** Fetch all top-level dashboard view definitions from active plugins */
+export async function fetchPluginDashboardViews(projectId?: string): Promise<PluginDashboardViewEntry[]> {
+  return api<PluginDashboardViewEntry[]>(withProjectId("/plugins/dashboard-views", projectId));
+}
+
 /** Fetch all plugin runtime metadata from active plugins */
 export async function fetchPluginRuntimes(projectId?: string): Promise<PluginRuntimeInfo[]> {
   return api<PluginRuntimeInfo[]>(withProjectId("/plugins/runtimes", projectId));