Mem-Client: MDS Storybook Completeness

MDS component Storybook coupling rule.

Scope:
- Applies to component source changes under `domains/frontend/mem-client/src/mds/components/**`.
- Ignore pure story-only, style-only, type-only, and barrel-only changes (`*.stories.tsx`, `*.style.tsx`, `*.types.ts`, `index.ts`).

Trigger A (new component source file):
- A new component `*.tsx` file is added in an MDS component folder.

Trigger B (existing component source file change):
- A component `*.tsx` file is modified and that folder already has a sibling `*.stories.tsx` file.

Hard requirements:
1) Trigger A requires a sibling `*.stories.tsx` file in the same component folder in the same PR.
2) Trigger B requires the sibling `*.stories.tsx` file to be updated in the same PR.

Decision:
- Return NOT APPROVED when Trigger A or Trigger B is met and story updates are missing.