feat(shared-filesystem-storage): migrates replicas to functional TypeScript (#1966)

[hodanoori]

Summary

Migrates ReplicaList and ReplicaItem components in the shared filesystem storage plugin to TypeScript as part of the React 19 migration epic (#1774). ReplicaList is converted from a class component to a functional component; ReplicaItem was already functional and is converted to TypeScript.

Changes Made

• Replace class component ReplicaList with a functional TypeScript component in list.tsx
• Convert ReplicaItem from JSX to TypeScript in item.tsx (already functional)
• Replace componentDidMount and UNSAFE_componentWillReceiveProps with useEffect([active]) in ReplicaList
• Add TypeScript interfaces for Replica, Share, SharesState, and component props in both files
• Add type declaration for lib/policy in app/javascript/types/global.d.ts
• Add list.test.tsx with 9 unit tests covering loading state, table rendering, and dependency loading
• Add item.test.tsx with 15 unit tests covering row rendering and actions menu

Related Issues

• Issue: closes [Task](shared-filesystem-replicas-list): Migrate shared_filesystem_storage/components/replicas/list.jsx #1966
• Epic: [EPIC](react-19): Upgrade to React 19 #1774

Screenshots (if applicable)

Checklist

• I have performed a self-review of my code.
• I have commented my code, particularly in hard-to-understand areas.
• I have added tests that prove my fix is effective or that my feature works.
• New and existing unit tests pass locally with my changes.
• I have made corresponding changes to the documentation (if applicable).
• My changes generate no new warnings or errors.