fix(openai-shim): restore provider coverage and array content guard

Keep relocated openaiShim suite tests in test:provider, and reject
non-object array content parts the same way the inline converter did.

package.json

@@ -68,7 +68,7 @@
     "install:verify": "bun run scripts/verify-clean-install.ts",
     "install:verify:published": "bun run scripts/verify-clean-install.ts --published",
     "build:verified": "bun run build && bun run verify:privacy",
-    "test:provider": "bun test --feature=UNATTENDED_RETRY --max-concurrency=1 src/services/api/*.test.ts src/utils/context.test.ts",
+    "test:provider": "bun test --feature=UNATTENDED_RETRY --max-concurrency=1 src/services/api/*.test.ts src/services/api/openaiShim/*.test.ts src/utils/context.test.ts",
     "doctor:runtime": "bun run scripts/system-check.ts",
     "doctor:runtime:json": "bun run scripts/system-check.ts --json",
     "doctor:report": "bun run scripts/system-check.ts --out reports/doctor-runtime.json",

src/services/api/openaiShim/responseConversion.test.ts

@@ -203,12 +203,17 @@ test('preserves structured Gemini signatures and safety terminal responses', ()
 })
 
 test('normalizes array content and length stop reasons', () => {
+  const functionPart = Object.assign(() => {}, {
+    type: 'text' as const,
+    text: 'ignored-fn',
+  })
   const message = convert({
     choices: [{
       message: {
         content: [
           { type: 'text', text: 'first' },
           { type: 'image' },
+          functionPart,
           { type: 'text', text: 'second' },
         ],
       },

src/services/api/openaiShim/responseConversion.ts

@@ -69,8 +69,16 @@ export function convertNonStreamingResponseToAnthropicMessage(
     ? choice.message.content : null
   if (typeof rawContent === 'string' && rawContent) appendTextOrRecoveredToolCalls(rawContent)
   else if (Array.isArray(rawContent)) {
-    const text = rawContent.filter(part => part?.type === 'text' && typeof part.text === 'string')
-      .map(part => part.text!).join('\n')
+    const text = rawContent
+      .filter(
+        part =>
+          part &&
+          typeof part === 'object' &&
+          part.type === 'text' &&
+          typeof part.text === 'string',
+      )
+      .map(part => part.text!)
+      .join('\n')
     if (text) appendTextOrRecoveredToolCalls(text)
   }