fix: namespace localStorage keys to prevent multi-instance contention

[samanthataylor3]

Closes #5

Describe your changes:

Multiple Open MCT instances running on the same host:port previously collided on bare localStorage keys (e.g. mct-recent-objects, notebook-storage, tcHistory). This PR introduces a centralized StorageManager utility that optionally prefixes all keys with a configurable namespace.

Architecture:

openmct.setStorageNamespace('instance-A');
// All subsequent storage calls produce keys like: "instance-A:mct-recent-objects"

Key changes:

• src/utils/StorageManager.js — new utility: _prefixKey(key) returns namespace ? namespace:key : key
• openmct.storage exposed on the MCT instance; openmct.setStorageNamespace(ns) API for configuration before start()
• All 12+ localStorage call sites refactored to go through openmct.storage.{getItem,setItem,removeItem}
• LocalStorageObjectProvider now accepts the StorageManager instance for its space key operations
• Standalone singletons (StylesManager, notebook-storage) accept storage via setStorage() / setNotebookStorage() hooks called at plugin install time
• StoragePersistence (user roles) refactored from a singleton to a class instantiated with storage
• Default namespace is '' (empty string) → no prefix → fully backward compatible

Files refactored:

Key	File(s)
mct-recent-objects	src/ui/layout/RecentObjectsList.vue
mct-tree-expanded	src/ui/layout/MctTree.vue
mct-pane-positions	src/ui/layout/PaneContainer.vue
mct-saved-styles	src/plugins/inspectorViews/styles/StylesManager.js
openmct-stored-view-prefs	src/ui/layout/BrowseBar.vue, src/ui/router/Browse.js
openmct-shell-head	src/ui/layout/AppLayout.vue
notebook-storage	src/plugins/notebook/utils/notebook-storage.js
notebook-snapshot-storage	src/plugins/notebook/snapshot-container.js
ACTIVE_USER_ROLE	src/api/user/StoragePersistence.js
tcHistory*	src/plugins/timeConductor/ConductorHistory.vue
openmct-listview-sort-order / storageKey	src/plugins/folderView/components/ListView.vue, src/ui/components/List/ListView.vue
mct (spaceKey)	src/plugins/localStorage/LocalStorageObjectProvider.js

All Submissions:

• Have you followed the guidelines in our Contributing document?
• Have you checked to ensure there aren't other open Pull Requests for the same update/change?
• Is this a notable change that will require a special callout in the release notes? For example, will this break compatibility with existing APIs or projects that consume these plugins?

Author Checklist

• Changes address original issue?
• Tests included and/or updated with changes?
• Has this been smoke tested?
• Have you associated this PR with a type: label? Note: this is not necessarily the same as the original issue.
• Have you associated a milestone with this PR? Note: leave blank if unsure.
• Testing instructions included in associated issue OR is this a dependency/testcase change?

Reviewer Checklist

• Changes appear to address issue?
• Reviewer has tested changes by following the provided instructions?
• Changes appear not to be breaking changes?
• Appropriate automated tests included?
• Code style and in-line documentation are appropriate?

Link to Devin session: https://app.devin.ai/sessions/9df1d5119fef4e4fbdd1b57e62809416
Requested by: @samanthataylor3

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[devin-ai-integration]

Original prompt from Samantha

Fix GitHub Issue #5 in COG-GTM/openmct: Multiple Open MCT instances cause LocalStorage contention.

#``# Problem
Open MCT uses bare localStorage keys (e.g., 'mct-recent-objects', 'mct-tree-expanded', 'notebook-storage') for UI state persistence. When multiple Open MCT instances run on the same host:port, they collide on these keys.

#``# Plan

#``#``# Step 1: Create centralized StorageManager utility
Create src/utils/StorageManager.js:

class StorageManager {
  constructor(namespace = '') {
    this.namespace = namespace;
  }
  _prefixKey(key) {
    return this.namespace ? `${this.namespace}:${key}` : key;
  }
  getItem(key) {
    return window.localStorage.getItem(this._prefixKey(key));
  }
  setItem(key, value) {
    window.localStorage.setItem(this._prefixKey(key), value);
  }
  removeItem(key) {
    window.localStorage.removeItem(this._prefixKey(key));
  }
}
export default StorageManager;

#``#``# Step 2: Register StorageManager on the OpenMCT instance
In src/MCT.js (or wherever the OpenMCT class is defined), add:

import StorageManager from './utils/StorageManager.js';
// In constructor or install:
this.storage = new StorageManager(options.storageNamespace || '');

This lets users pass storageNamespace when creating their OpenMCT instance.

#``#``# Step 3: Refactor ALL localStorage call sites
Here is the complete list of files and keys to refactor:

Key	File(s)
mct-recent-objects	src/ui/layout/RecentObjectsList.vue
mct-tree-expanded	src/ui/layout/MctTree.vue
mct-pane-positions	src/ui/layout/PaneContainer.vue
mct-saved-styles	src/plugins/inspectorViews/styles/StylesManager.js
openmct-stored-view-prefs	src/ui/layout/BrowseBar.vue, src/ui/router/Browse.js
openmct-shell-head	src/ui/layout/AppLayout.vue
notebook-storage	src/plugins/notebook/utils/notebook-storage.js
notebook-snapshot-storage	src/plugins/notebook/snapshot-container.js
`ACTIVE_USER_ROLE... (1151 chars truncated...)

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