#11526: fix(control-ui): hide tool-only assistant messages when thinking is off

## Bug When the thinking toggle is off, messages with role `toolresult` are correctly hidden. However, assistant messages that contain **only** tool calls (`toolcall`/`tool_call`/`tooluse`/`tool_use`) or `thinking` blocks are still displayed as empty bubbles in the chat. ## Fix Add a check to also skip assistant messages where every content block is a tool call or thinking block, matching the existing behavior for toolresult messages. ## Changes - `ui/src/ui/views/chat.ts`: Added filtering for tool-only assistant messages when `showThinking` is false Small, surgical fix — one file, no new dependencies. <!-- greptile_comment --> <h2>Greptile Overview</h2> <h3>Greptile Summary</h3> This change updates `buildChatItems` in `ui/src/ui/views/chat.ts` to additionally skip assistant messages when `showThinking` is false and the message’s `content` blocks are all tool-call or `thinking` blocks, preventing empty-looking chat bubbles. The approach matches the existing behavior that already hides `toolresult` messages when thinking is off, but it currently relies on `raw.content` being a non-empty array, which may not cover all “empty bubble” shapes (e.g., assistant messages with missing/empty `content`). <h3>Confidence Score: 4/5</h3> - Generally safe to merge, but verify it covers all empty assistant-message shapes. - The change is localized and low-impact, but the new filter only triggers when `raw.content` is a non-empty array; if the empty-bubble messages in practice have empty/missing content, the bug can persist and should be addressed before merge. - ui/src/ui/views/chat.ts <!-- greptile_other_comments_section --> <!-- /greptile_comment -->