Agent: carmack
Changes:
- streaming_parser.rs: Unified find_first/last_tool_call_start into single
find_tool_call_start with SearchDirection enum, reducing duplication.
Simplified is_json_invalidated from 45 to 20 lines with clearer logic.
Fixed redundant !escape_next check in find_complete_json_object_end.
- filter_json.rs: Simplified check_tool_pattern from 40 to 24 lines.
Replaced repetitive prefix checks with loop over ["t", "to", "too", "tool"].
Reduced trailing return statements with direct expression returns.
- ui_writer_impl.rs: Added ansi module for duration color constants.
Simplified duration_color function by removing redundant comments.
- language_prompts.rs: Fixed test assertions to match actual prompt content
("obvious, readable Racket" instead of "RACKET-SPECIFIC GUIDANCE").
All 174+ tests pass. No behavior changes.