test(ai-sdk): cover v7 inline file attachments in e2e and re-record

- Keep the AI SDK v7 `{ type: "data", data }` envelope when logging inline
  file bytes as attachments, matching the decision-image logging shape.
- Add a streamText image-file e2e operation (v5+, tagged data on v7) that
  asserts file bytes are logged as attachments on both the parent and
  model spans. It fails without the fix.
- Replace the plugin unit test and two live-API wrapper image tests with
  this e2e coverage, and drop the unused test-image.png fixture.
- Move the scenario off the deprecated gpt-4.1-nano and gpt-4o-mini to
  gpt-5.4-nano (v3 keeps gpt-4o-mini because its provider sends
  max_tokens), send prior tool items inline with store: false, and
  re-record all cassettes and snapshots.

Author: AbhiPrasad

.changeset/ai-sdk-v7-inline-file-attachments.md

@@ -2,4 +2,4 @@
 "braintrust": patch
 ---
 
-fix(ai-sdk): log AI SDK v7 inline file data as attachments instead of copying the bytes into the span
+fix(ai-sdk): log AI SDK v7 inline file data as attachments