refactor(sdk): narrow response fallbacks

Replace unsafe unknown-array assertions with generic fallback types and explicit todo status narrowing.

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/hooks/read-image-resizer/hook.ts

@@ -189,8 +189,8 @@ export function createReadImageResizerHook(_ctx: PluginInput) {
         }
       }
 
-      if (attachmentsToRemove.length > 0) {
-        const rawAttachments = outputRecord.attachments as unknown[]
+      if (attachmentsToRemove.length > 0 && Array.isArray(outputRecord.attachments)) {
+        const rawAttachments = outputRecord.attachments
         for (const toRemove of attachmentsToRemove) {
           const removeIndex = rawAttachments.indexOf(toRemove)
           if (removeIndex !== -1) {