feat(provider): add preserveReasoningInContent config option and remove isQwen auto-detection

Author: jgrcic

packages/opencode/src/config/provider.ts

@@ -53,7 +53,16 @@ export const Model = Schema.Struct({
   provider: Schema.optional(
     Schema.Struct({ npm: Schema.optional(Schema.String), api: Schema.optional(Schema.String) }),
   ),
-  options: Schema.optional(Schema.Record(Schema.String, Schema.Any)),
+  options: Schema.optional(
+    Schema.StructWithRest(
+      Schema.Struct({
+        preserveReasoningInContent: Schema.optional(Schema.Boolean).annotate({
+          description: "When true, formats reasoning history as <thinking> tags within the content instead of using reasoning_content (required for Qwen3.6 preserve_thinking)."
+        })
+      }),
+      [Schema.Record(Schema.String, Schema.Any)]
+    )
+  ),
   headers: Schema.optional(Schema.Record(Schema.String, Schema.String)),
   variants: Schema.optional(
     Schema.Record(

packages/opencode/src/provider/transform.ts

@@ -214,12 +214,11 @@ function normalizeMessages(
     })
   }
 
-  const isQwen = model.id.toLowerCase().includes("qwen") || model.api.id.toLowerCase().includes("qwen")
   const preserveReasoningInContent =
     _options?.preserveReasoningInContent === true ||
     (model.options as any)?.preserveReasoningInContent === true
 
-  if (isQwen || preserveReasoningInContent) {
+  if (preserveReasoningInContent) {
     msgs = msgs.map((msg) => {
       if (msg.role === "assistant" && Array.isArray(msg.content)) {
         const reasoningParts = msg.content.filter((part: any) => part.type === "reasoning")