Bug type

Crash (process/app exits or hangs)

Summary

promoteThinkingTagsToBlocks can throw when assistant content contains malformed non-object entries (e.g. null) because it reads block.type without a guard.

Steps to reproduce

1. Construct an assistant message with content: [null, {"type":"text","text":"ok"}].
2. Call promoteThinkingTagsToBlocks(message).
3. Observe a throw: Cannot read properties of null (reading 'type').

Expected behavior

Malformed content entries should be passed through unchanged (or ignored), and thinking-tag promotion should not throw.

Actual behavior

Function throws before processing content.

Root cause

In src/agents/pi-embedded-utils.ts, message.content.some((block) => block.type === "thinking") and loop branches dereference block.type without validating block shape.

Proposed fix

Add object/type guards before reading block.type and keep existing behavior for well-formed blocks.