- Add generateDiffString() function in edit tool to create unified diffs with line numbers and 4 lines of context
- Store only the formatted diff string in tool result details instead of full file contents
- Update tool-execution renderer to parse and colorize the diff string
- Filter out message_update events from session saving to prevent verbose session files
- Add markdown nested list and table rendering tests
**Improved output messages:**
1. File fits within limits: Just outputs content (no notices)
2. Lines get truncated: Shows "Some lines were truncated to 2000 characters for display"
3. File doesn't fit limit: Shows "N more lines not shown. Use offset=X to continue reading"
4. Offset beyond file: Shows "Error: Offset X is beyond end of file (N lines total)"
5. Both truncations: Combines both notices with ". " separator
**Comprehensive test coverage:**
- Files within limits (no notices)
- Large files (line truncation)
- Long lines (character truncation)
- Offset parameter
- Limit parameter
- Offset + limit together
- Invalid offset (out of bounds)
- Combined truncations (both notices)
All 17 tests passing ✓
Tool results now use content blocks and can include both text and images.
All providers (Anthropic, Google, OpenAI Completions, OpenAI Responses)
correctly pass images from tool results to LLMs.
- Update ToolResultMessage type to use content blocks
- Add placeholder text for image-only tool results in Google/Anthropic
- OpenAI providers send tool result + follow-up user message with images
- Fix Anthropic JSON parsing for empty tool arguments
- Add comprehensive tests for image-only and text+image tool results
- Update README with tool result content blocks API
