This is an automated backport of #12353 to the release-v5.0 branch.

---------

Co-authored-by: Felix Arntz <felix.arntz@vercel.com>
Co-authored-by: Gregor Martynus <39992+gr2m@users.noreply.github.com>

…es (#12375)

## Background

When streaming with the `anthropic` provider, `response.usage.raw` only
contained the 4 explicitly typed fields (`input_tokens`,
`output_tokens`, `cache_creation_input_tokens`,
`cache_read_input_tokens`) instead of the full raw API response. The raw
response from Anthropic's API includes additional fields like
`service_tier`, `inference_geo`, `cache_creation`, and `server_tool_use`
that were being lost. This worked correctly for `generateText` but not
`streamText`.

Discovered this while working on #12353: when streaming with
`speed=fast`, with this PR enabled you'll see it in the response -
without it you weren't even though it was already being used.

## Summary

Fixed the `doStream` method to pass the full `rawUsage` JSONObject
(which accumulates all fields from stream chunks) to
`convertAnthropicMessagesUsage` instead of the typed `usage` object
(which only has the 4 declared properties).

This also fixes a secondary bug in multi-turn streaming (programmatic
tool calling): the typed `usage` object was mutated in place across
turns, but `raw` held a reference to this same mutable object, causing
all turns to show the last turn's token values. The fix resolves this
because `rawUsage` is replaced (not mutated) at each `message_start`.

**Changes:**
- Updated `convertAnthropicMessagesUsage` to accept `{ usage, rawUsage?
}` object instead of just `usage`, using `rawUsage` for the `raw` field
when provided
- Updated both call sites (`doGenerate` and `doStream`) to use the new
signature
- Added comprehensive unit tests for the usage conversion function
- Updated test snapshots to reflect the now-correct raw usage data

## Manual Verification

Run this without the PR, and then again with the PR:
```bash
cd examples/ai-functions
pnpm tsx src/generate-text/anthropic.ts
pnpm tsx src/stream-text/anthropic.ts
cd ../..
```

The `generateText` result will always include actual raw data, e.g.
`service_tier`, while the `streamText` result will not. With the PR, the
`streamText` result will correctly include those additional values.

## Checklist

- [x] Tests have been added / updated (for bug fixes / features)
- [ ] Documentation has been added / updated (for bug fixes / features)
- [x] A _patch_ changeset for relevant packages has been added (for bug
fixes / features - run `pnpm changeset` in the project root)
- [x] I have reviewed this pull request (self-review)

## Related Issues

N/A

…ard (#12582)

## Background

Follow-up to #12353 which added `speed: 'fast'` support for Claude. A
few things were missed: `'standard'` is also a valid value per the
Anthropic spec, the `speed` field was missing from the API type
definitions, and there was no documentation for the feature.

These are low-severity issues, but potentially could lead to problems
for those that rely on `providerOptions` schema and may incorrectly
reject the `'standard'` value.

## Summary

- Accept `'standard'` in addition to `'fast'` for the `speed` provider
option (it's a no-op but required by the spec)
- Add `AnthropicSpeed` type to the API definitions
- Add a "Fast Mode" section to the Anthropic provider docs
- Add test for `speed: 'standard'` verifying no beta header is sent

## Checklist

- [x] Tests have been added / updated (for bug fixes / features)
- [x] Documentation has been added / updated (for bug fixes / features)
- [x] A _patch_ changeset for relevant packages has been added (for bug
fixes / features - run `pnpm changeset` in the project root)
- [x] I have reviewed this pull request (self-review)

## Related Issues

N/A

…ard (#12582)

## Background

Follow-up to #12353 which added `speed: 'fast'` support for Claude. A
few things were missed: `'standard'` is also a valid value per the
Anthropic spec, the `speed` field was missing from the API type
definitions, and there was no documentation for the feature.

These are low-severity issues, but potentially could lead to problems
for those that rely on `providerOptions` schema and may incorrectly
reject the `'standard'` value.

## Summary

- Accept `'standard'` in addition to `'fast'` for the `speed` provider
option (it's a no-op but required by the spec)
- Add `AnthropicSpeed` type to the API definitions
- Add a "Fast Mode" section to the Anthropic provider docs
- Add test for `speed: 'standard'` verifying no beta header is sent

## Checklist

- [x] Tests have been added / updated (for bug fixes / features)
- [x] Documentation has been added / updated (for bug fixes / features)
- [x] A _patch_ changeset for relevant packages has been added (for bug
fixes / features - run `pnpm changeset` in the project root)
- [x] I have reviewed this pull request (self-review)

## Related Issues

N/A