ref(ai-sdk)!: Remove AI SDK v3 support

.changeset/remove-ai-sdk-v3.md

@@ -0,0 +1,5 @@
+---
+"braintrust": major
+---
+
+ref(ai-sdk)!: Remove AI SDK v3 support

e2e/README.md

@@ -80,7 +80,7 @@ Wrapper scenarios often create a root span with `testRunId` metadata and then le
 - Find the scenario root span first.
 - Scope raw payload snapshots by `root_span_id` using `payloadRowsForRootSpan(...)`.
 - Prefer normalized span-tree snapshots from `matchSpanTreeSnapshot(...)`. The `.json` sibling is the structural contract, and the `.txt` sibling is the ASCII tree for review; both are asserted and should be updated together.
-- If the wrapper has an explicit support matrix, reuse one shared test across version-specific scenario entries instead of duplicating the assertions. The AI SDK wrapper scenario uses this for supported v3-v6 package combinations.
+- If the wrapper has an explicit support matrix, reuse one shared test across version-specific scenario entries instead of duplicating the assertions. The AI SDK wrapper scenario uses this for its supported package combinations.
 
 ### Runner-wrapper scenario pattern
 

e2e/config/pr-comment-scenarios.json

@@ -531,14 +531,6 @@
     "label": "AI SDK Instrumentation",
     "metadataScenario": "ai-sdk-instrumentation",
     "variants": [
-      {
-        "variantKey": "ai-sdk-v3",
-        "label": "v3 pinned"
-      },
-      {
-        "variantKey": "ai-sdk-v3-latest",
-        "label": "v3 latest"
-      },
       {
         "variantKey": "ai-sdk-v4",
         "label": "v4 pinned"