fix(jupyter): replace manual index.html patching with config-based plugin (#114)

The postMessage signal AnalySim relies on to detect when JupyterLite is
ready was injected by patching a manually copied index.html file. Every
jupyter lite build regenerates that file, silently wiping the patch out.
This is why upgrading JupyterLite has historically required manual work.

Changes in this commit:

- analysim_notifier plugin: the postMessage logic now lives in a proper
  JupyterLite plugin using app.started, which is the stable API for this.
  The plugin survives version upgrades without any manual steps.

- jupyter_lite_config.json: explicit build config so output directory is
  always dist/ and no manual steps are needed after building.

- jupyter-lite.json: runtime config for app name and extension settings,
  previously absent entirely.

- overrides.json: UI defaults (theme) in one declarative place.

- Consolidated JupyterLiteStorageService: the service existed in two
  near-identical copies in admin and project folders. Moved to
  app/shared/services/ with old files re-exporting for compatibility.

- Fixed event listener leak in ProjectNotebookItemDisplayComponent:
  the window message listener added in ngOnInit was never removed in
  ngOnDestroy, causing listeners to accumulate on repeated opens.

Fixes #114

Author: Dbansal06

src/Analysim.Web/ClientApp/src/app/admin/components/notebooks/admin-notebook-item/admin-notebook-item-display/forageIndexDb.ts

@@ -1,49 +1,3 @@
-import { Injectable } from '@angular/core';
-import * as localforage from 'localforage';
-
-@Injectable({
-    providedIn: 'root',
-})
-export class JupyterLiteStorageService {
-    private filesStore: LocalForage;
-    private checkpointsStore: LocalForage;
-
-    constructor() {
-        this.filesStore = localforage.createInstance({
-            name: 'JupyterLite Storage',
-            storeName: 'files', // Object store name
-            description: 'Storage for JupyterLite files',
-        });
-        this.checkpointsStore = localforage.createInstance({
-            name: 'JupyterLite Storage',
-            storeName: 'checkpoints', // Object store name
-            description: 'Storage for JupyterLite checkpoints',
-        });
-    }
-
-    // Add a file to the IndexedDB
-    addFile(fileName: string, fileData: any): Promise<any> {
-        return this.filesStore.setItem(fileName, fileData);
-    }
-
-    // Get a file by its name
-    getFile(fileName: string): Promise<any> {
-        return this.filesStore.getItem(fileName);
-    }
-
-    getCheckpoints(fileName: string): Promise<any> {
-        return this.checkpointsStore.getItem(fileName);
-    }
-
-    removeFile(fileName: string): Promise<any> {
-        return this.filesStore.removeItem(fileName);
-    }
-
-    // Get all files
-    getAllFiles(): Promise<any[]> {
-        const files: any[] = [];
-        return this.filesStore.iterate((value, key) => {
-            files.push({ key, value });
-        }).then(() => files);
-    }
-}
+// JupyterLiteStorageService has been consolidated into a shared service.
+// This file re-exports from the new location for backwards compatibility.
+export { JupyterLiteStorageService } from '../../../../../shared/services/jupyter-lite-storage.service';