fix: filter empty/whitespace text content blocks at provider boundaries

Skip empty and whitespace-only text content blocks at each provider's
message conversion layer, preventing 400 errors from Anthropic, Bedrock,
Venice, and other OpenAI-compatible APIs.

- Anthropic: check .trim() instead of truthiness in convertMessageContentToBlocks
- Bedrock (core): skip empty text in _convertMessageContentToBlocks
- Bedrock (adapter): skip empty text parts in user message conversion
- OpenAI adapter: filter empty text parts from assistant array content

Fixes #9232, #9765, #9767, #10148, #10293, #10504, #10804, #11045,
#11264, #11446, #11497, #11728

Author: RomneyDa

core/llm/llms/Anthropic.ts

@@ -90,7 +90,7 @@ class Anthropic extends BaseLLM {
   ): ContentBlockParam[] {
     const parts: ContentBlockParam[] = [];
     if (typeof content === "string") {
-      if (content) {
+      if (content.trim()) {
         parts.push({
           type: "text",
           text: content,
@@ -99,7 +99,7 @@ class Anthropic extends BaseLLM {
     } else {
       for (const part of content) {
         if (part.type === "text") {
-          if (part.text) {
+          if (part.text?.trim()) {
             parts.push({
               type: "text",
               text: part.text,

core/llm/llms/Bedrock.ts

@@ -538,11 +538,15 @@ class Bedrock extends BaseLLM {
   ): ContentBlock[] {
     const blocks: ContentBlock[] = [];
     if (typeof content === "string") {
-      blocks.push({ text: content });
+      if (content.trim()) {
+        blocks.push({ text: content });
+      }
     } else {
       for (const part of content) {
         if (part.type === "text") {
-          blocks.push({ text: part.text });
+          if (part.text?.trim()) {
+            blocks.push({ text: part.text });
+          }
         } else if (part.type === "imageUrl" && part.imageUrl) {
           const parsed = parseDataUrl(part.imageUrl.url);
           if (parsed) {

core/llm/openaiTypeConverters.ts

@@ -149,7 +149,7 @@ export function toChatMessage(
         typeof message.content === "string"
           ? message.content || " " // LM Studio (and other providers) don't accept empty content
           : message.content
-              .filter((part) => part.type === "text")
+              .filter((part) => part.type === "text" && part.text?.trim())
               .map((part) => part as TextMessagePart),
     };
 

packages/openai-adapters/src/apis/Bedrock.ts

@@ -203,9 +203,14 @@ export class BedrockApi implements BaseLlmApi {
           const content = message.content;
           if (content) {
             if (typeof content === "string") {
-              currentBlocks.push({ text: content });
+              if (content.trim()) {
+                currentBlocks.push({ text: content });
+              }
             } else {
               content.forEach((part) => {
+                if (part.type === "text" && !part.text?.trim()) {
+                  return;
+                }
                 currentBlocks.push(this._oaiPartToBedrockPart(part));
               });
             }