refactor: flatten Microsoft skills from nested to flat directory structure

Rewrote sync_microsoft_skills.py (v4) to use each SKILL.md's frontmatter
'name' field as the flat directory name under skills/, replacing the nested
skills/official/microsoft/<lang>/<category>/<service>/ hierarchy.

This fixes CI failures caused by the indexing, validation, and catalog
scripts expecting skills/<id>/SKILL.md (depth 1).

Changes:
- Rewrite scripts/sync_microsoft_skills.py for flat output with collision detection
- Update scripts/tests/inspect_microsoft_repo.py for flat name mapping
- Update scripts/tests/test_comprehensive_coverage.py for name uniqueness checks
- Delete skills/official/ nested directory
- Add 129 Microsoft skills as flat directories (e.g. skills/azure-mgmt-botservice-dotnet/)
- Move attribution files to docs/ (LICENSE-MICROSOFT, microsoft-skills-attribution.json)
- Rebuild skills_index.json, CATALOG.md, README.md (845 total skills)

skills/zustand-store-ts/SKILL.md

@@ -0,0 +1,68 @@
+---
+name: zustand-store-ts
+description: Create Zustand stores with TypeScript, subscribeWithSelector middleware, and proper state/action separation. Use when building React state management, creating global stores, or implementing reactive state patterns with Zustand.
+---
+
+# Zustand Store
+
+Create Zustand stores following established patterns with proper TypeScript types and middleware.
+
+## Quick Start
+
+Copy the template from [assets/template.ts](assets/template.ts) and replace placeholders:
+- `{{StoreName}}` → PascalCase store name (e.g., `Project`)
+- `{{description}}` → Brief description for JSDoc
+
+## Always Use subscribeWithSelector
+
+```typescript
+import { create } from 'zustand';
+import { subscribeWithSelector } from 'zustand/middleware';
+
+export const useMyStore = create<MyStore>()(
+  subscribeWithSelector((set, get) => ({
+    // state and actions
+  }))
+);
+```
+
+## Separate State and Actions
+
+```typescript
+export interface MyState {
+  items: Item[];
+  isLoading: boolean;
+}
+
+export interface MyActions {
+  addItem: (item: Item) => void;
+  loadItems: () => Promise<void>;
+}
+
+export type MyStore = MyState & MyActions;
+```
+
+## Use Individual Selectors
+
+```typescript
+// Good - only re-renders when `items` changes
+const items = useMyStore((state) => state.items);
+
+// Avoid - re-renders on any state change
+const { items, isLoading } = useMyStore();
+```
+
+## Subscribe Outside React
+
+```typescript
+useMyStore.subscribe(
+  (state) => state.selectedId,
+  (selectedId) => console.log('Selected:', selectedId)
+);
+```
+
+## Integration Steps
+
+1. Create store in `src/frontend/src/store/`
+2. Export from `src/frontend/src/store/index.ts`
+3. Add tests in `src/frontend/src/store/*.test.ts`