fix(useTextDirection): read the document direction on the first render

[rawsun007]

Description

useTextDirection destructures initialValue with a default:

const { selector = 'html', initialValue = 'ltr' } = options
const getValue = () => {
  if (initialValue !== undefined) {
    return initialValue          // always taken
  }
  if (isBrowser) { ...read the dir attribute... }   // dead
  ...server-side warning...                          // dead
}

Because of the default, initialValue !== undefined is always true, so the branch that reads the element's dir and the SSR warning below it are both unreachable.

The effect corrects the value after mount, so what is left is a wrong first render. Recording the value on every render, on a document with dir="rtl":

before: ["ltr", "rtl"]
after:  ["rtl"]

That is a flash on the client and, under SSR, markup that says ltr for an RTL document — which is the mismatch the dead warning was written to prevent.

Now the document wins, falling back to initialValue and then 'ltr', which is what the unreachable branch already did and matches VueUse's useTextDirection. initialValue still defaults to 'ltr' in effect, so nothing changes for a document that sets no dir.

Type of Change

• Bug fix
• New hook
• Enhancement to existing hook
• Documentation update
• Other (please describe)

Checklist

• I have read the Contributing Guide
• I have read and understood every line of this diff myself, including any AI-written parts (AI usage policy)
• My code follows the project's coding style
• I have added tests for my changes
• All existing tests pass
• I have updated the documentation

---

The hook had no spec; this adds five. Mutation check: reverting only index.ts fails exactly the two that pin the new behaviour (first render on an RTL document, and document-over-initialValue), while the three that describe unchanged behaviour stay green.

jest 427 passing, eslint clean, tsc --noEmit clean. No interface.ts change, so no docs regeneration — @defaultValue 'ltr' is still accurate, it is now the fallback when the element carries no dir.

The diff was written by Claude Opus 5 in Claude Code under my direction; I have not read it line by line myself yet, so that box stays unticked until I have.

🤖 Generated with Claude Code

[childrentime]

Verified locally: reverting only index.ts fails exactly the two specs that pin the new behaviour, and the SSR path now emits the warning it was always meant to. Thanks!