fix: typos in JSDoc, comments, and test descriptions

[andromia3]

No functional changes. Every edit is to an inline comment, a JSDoc string, or a test-description string passed to `describe`/`it`. No identifiers, no runtime behaviour, no public API shape touched.

JSDoc on public API

These two live on public types and show up in IDE tooltips + shopify.dev:

• `packages/hydrogen/src/analytics-manager/AnalyticsProvider.tsx` — `AnalyticsProviderProps.canTrack`:
  ```diff
• /** An optional function to set wether the user can be tracked. ... */

• /** An optional function to set whether the user can be tracked. ... */
  ```

• `packages/hydrogen/src/seo/generate-seo-tags.ts` — `SeoConfig.media` `@example`:
  ```diff

• •   altText: 'A custom snowboard with an alpine color pallet.',
    

• •   altText: 'A custom snowboard with an alpine color palette.',
    

```
("pallet" = shipping platform; "palette" = range of colours.)

Because both strings are mirrored into `packages/hydrogen/docs/generated/generated_docs_data.json` (committed alongside source), that file is updated in the same commit so it stays in sync. If anything drifted, `pnpm run build-docs` would regenerate cleanly.

Comments in a CLI skeleton asset

`packages/cli/assets/routes/locale-check.ts`:
```diff

• // If the locale URL param is defined, yet we still are still at the default locale
• // then the the locale param must be invalid, send to the 404 page

• // If the locale URL param is defined, yet we are still at the default locale
• // then the locale param must be invalid, send to the 404 page
  ```
  Two independent typos on consecutive lines: a duplicated `still` and a duplicated `the`.

Test-description strings

All are just strings in `it(...)` / `describe(...)` — renaming them is risk-free (no identifiers reference them).

• `packages/hydrogen-codegen/tests/client.test-d.ts` — `fallsback` → `falls back`; `overriden` → `overridden`.
• `packages/hydrogen/src/storefront.test.ts` — `fallsback` → `falls back`.
• `packages/cli/src/lib/environment-variables.test.ts` — `doest not fail` → `does not fail`.
• `packages/hydrogen-react/src/AddToCartButton.test.tsx` — `explicity` → `explicitly` (x2, one `describe` and one nested `describe`).

---

No changeset: none of this is user-facing behaviour, and the Changeset Reminder workflow explicitly notes "If you are making simple updates to examples or documentation, you do not need to add a changeset."