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

plugins/fusion-plugin-dependency-graph/src/__tests__/storage.test.ts

@@ -0,0 +1,31 @@
+import { describe, expect, it, beforeEach } from "vitest";
+import { projectScopedKey, loadPositions, savePositions } from "../storage";
+
+const createMemoryStorage = () => {
+  const map = new Map<string, string>();
+  return {
+    getItem: (key: string) => map.get(key) ?? null,
+    setItem: (key: string, value: string) => {
+      map.set(key, value);
+    },
+    clear: () => map.clear(),
+  };
+};
+
+describe("storage", () => {
+  const localStorage = createMemoryStorage();
+
+  beforeEach(() => {
+    (globalThis as { window?: { localStorage?: typeof localStorage } }).window = { localStorage };
+    localStorage.clear();
+  });
+
+  it("builds project-scoped key", () => {
+    expect(projectScopedKey("proj_123")).toBe("kb:proj_123:dependency-graph-positions");
+  });
+
+  it("persists and restores positions", () => {
+    savePositions("proj_123", { "FN-1": { x: 10, y: 20 } });
+    expect(loadPositions("proj_123")).toEqual({ "FN-1": { x: 10, y: 20 } });
+  });
+});