feat(analytics): connect Umami analytics across www, docs, and static services (#49)

## Summary of Changes

- **`@ermnvldmr/ssg`**: Added extensible `AnalyticsProvider` interface,
`umamiAnalytics` integration in `@ermnvldmr/ssg/dev`, and runtime client
analytics dispatchers (`trackEvent`, `identifySession`).
- **`services/docs`**: Configured native Hextra Umami parameters in
`hugo.yaml` (`docs.ermnvldmr.com` with UUID
`fbdadf3f-3484-4186-a2c2-cedcf76cf44f`).
- **`services/www`**: Injected Umami tracking provider into
`rsbuild.config.ts` (`ermnvldmr.com`, `www.ermnvldmr.com` with UUID
`4fca5ac2-4fe4-4626-b708-933c37bfe918`).
- **`services/static`**: Injected Umami tracking provider into
`rsbuild.config.ts` (`static.ermnvldmr.com` with UUID
`0831532a-2cec-4955-8f5b-452d8bba96d8`).
- **Environment & Privacy**: Injections are automatically disabled in
development builds. Configured `data-domains` filtering and
`data-do-not-track="true"`.

## Verification
- `pnpm typecheck`: Passed (0 errors)
- `pnpm lint`: Passed (0 warnings)
- `pnpm test`: Passed (all unit test suites)
- `pnpm build`: Passed clean workspace build and pre-rendered SSG
injection

---
Disclosure: I'm an AI assistant helping Vladimir Eremin; I'm not
Vladimir Eremin.

packages/stl/src/lib/react/filterDataAttributes/filterDataAttributes.test.ts

@@ -0,0 +1,33 @@
+import { describe, expect, it } from 'vitest';
+
+import { filterDataAttributes } from './filterDataAttributes';
+
+describe('filterDataAttributes', () => {
+  it('extracts all data-* attributes correctly', () => {
+    const props = {
+      id: 'button-1',
+      className: 'btn',
+      'data-testid': 'my-test-id',
+      'data-umami-event': 'click-me',
+      'data-umami-event-target': 'hero',
+      onClick: () => {},
+    };
+
+    const result = filterDataAttributes(props);
+    expect(result).toEqual({
+      'data-testid': 'my-test-id',
+      'data-umami-event': 'click-me',
+      'data-umami-event-target': 'hero',
+    });
+  });
+
+  it('returns an empty object when no data-* attributes are present', () => {
+    const props = {
+      id: 'header-1',
+      className: 'header',
+    };
+
+    const result = filterDataAttributes(props);
+    expect(result).toEqual({});
+  });
+});

packages/stl/src/lib/react/filterDataAttributes/filterDataAttributes.ts

@@ -0,0 +1,32 @@
+import type { DataAttributes } from '../../types/dataAttributes.js';
+
+/**
+ * Filters and extracts all `data-*` attributes from a props object.
+ *
+ * @param props - Source props object.
+ * @returns An object containing only the `data-*` attributes.
+ *
+ * @example
+ * ```typescript
+ * const dataAttrs = filterDataAttributes(props);
+ * ```
+ */
+export function filterDataAttributes<T extends object>(props: T): DataAttributes {
+  const result: DataAttributes = {};
+  for (const key in props) {
+    if (Object.prototype.hasOwnProperty.call(props, key) && key.startsWith('data-')) {
+      // eslint-disable-next-line @typescript-eslint/consistent-type-assertions
+      const value: unknown = (props as Record<string, unknown>)[key];
+      if (
+        typeof value === 'string' ||
+        typeof value === 'number' ||
+        typeof value === 'boolean' ||
+        value === undefined
+      ) {
+        // eslint-disable-next-line @typescript-eslint/consistent-type-assertions
+        result[key as `data-${string}`] = value;
+      }
+    }
+  }
+  return result;
+}

packages/stl/src/lib/react/index.ts

@@ -1,6 +1,7 @@
 export { castRef } from './castRef/castRef';
 export { castMutableRef } from './castRef/castMutableRef';
 export { genericMemo } from './genericMemo/genericMemo';
+export { filterDataAttributes } from './filterDataAttributes/filterDataAttributes';
 export { useResizeObserver } from './useResizeObserver/useResizeObserver';
 export { useIntersectionObserver } from './useIntersectionObserver/useIntersectionObserver';
 export { useScroll } from './useScroll/useScroll';

packages/stl/src/lib/types/dataAttributes.ts

@@ -0,0 +1,11 @@
+/**
+ * Type allowing arbitrary `data-*` attributes on component props.
+ *
+ * @example
+ * ```typescript
+ * interface ButtonProps extends DataAttributes {
+ *   children: React.ReactNode;
+ * }
+ * ```
+ */
+export type DataAttributes = Record<`data-${string}`, string | number | boolean | undefined>;

packages/stl/src/lib/types/index.ts

@@ -3,4 +3,5 @@
  */
 
 export type { ClassNameProps } from './classNameProps';
+export type { DataAttributes } from './dataAttributes';
 export type { TestIdProps } from './testIdProps';