refactor: decouple mock API data into separate fixtures file and upda…

[GiftedGiftB]

Closed #389

Description

This PR refactors the frontend mock database by decoupling static data fixtures from the mock API behavior. It also fixes several UI/UX bugs in the Admin Settings dashboard, resolving malformed component structures and fixing broken toast notification bindings.

Type of Change

• 🐛 Bug fix (UI or API integration)
• ✨ New feature / component
• 🎨 UI/UX improvement
• 📝 Documentation update
• 🔧 Chore / refactor / dependency update
• 🧪 Tests only

Changes Made

• lib/api/mock/fixtures.ts: [New File] Extracted all static mock fixtures (members, resources, policies, communities, webhook events, and seed naming pools) into a dedicated file.
• lib/api/mock.ts: Refactored to import static fixtures rather than declaring them inline, drastically simplifying the file and strictly separating state mutation behavior from data.
• app/[communitySlug]/admin/settings/page.tsx:
  • Fixed a build-breaking JSX error caused by an unclosed <Card> component and a duplicated Workflow & Approvals section.
  • Fixed useToasts() hook usage by properly destructuring toasts and dismissToast.
  • Added required toasts and onDismiss props to the <ToastViewport /> component to prevent invisible toast errors.
  • Corrected addToast options to use the valid tone property instead of variant.
• test/pending-actions.test.ts: Fixed severe test file corruption (duplicated imports and redefined block-scoped variables) that was failing the test suite.

Screenshots / Recordings

Before	After
Admin Settings failing to render / missing toasts	Admin Settings renders correctly with functioning toast notifications

Test Evidence

• Tested in mock mode (NEXT_PUBLIC_MOCK_MODE=true)
• Tested against live guildpass-core (if applicable)

Checklist

• I have read CONTRIBUTING.md
• This PR is linked to an open issue
• npm run typecheck passes
• npm run lint passes
• New components work in mock mode
• Loading, empty, and error states are handled in new feature modules
• No inline styles — Tailwind classes used throughout
• No secrets or API keys included
• .env.example updated if new environment variables were added
• Accessibility: interactive elements are keyboard-navigable and have ARIA labels where needed

Additional Notes

The Typescript configuration deprecation warnings from TS 5.x were also suppressed in the root and test tsconfig.json files to ensure a cleaner build output pipeline.