- Added a unified eval framework with parser grammar, backend interfaces, and JS/Python execution result types.
- Added eval tool docs and updated prompts for fenced cells, `eval.py`/`eval.js`, and fallback behavior.
- Replaced the built-in `python` tool with `eval` across registry, rendering, interactive modes, and tool settings.
- Migrated Python execution runtime from `src/ipy` to `src/eval/py`, renamed state fields, and removed legacy introspection.
- Refactored browser tooling from in-process VM helpers to worker-managed tab supervisors and protocol transport.
- Added eval parser fallback and JS tool-bridge tests, updated imports, and removed obsolete python-mode suites.
- Tracked locally submitted user signatures for both optimistic and streamed-queue submissions in interactive-mode context state.
- Updated user message_start handling to avoid re-clearing the editor and re-adding chat for locally originated messages.
- Cleared consumed local signatures on queued-message restore and added tests for queued, external, and optimistic message_start editor behavior.
- Introduced SubmittedUserInput type to track submission state including cancelled and started flags. Added startPendingSubmission, cancelPendingSubmission, markPendingSubmissionStarted, and finishPendingSubmission methods to manage the lifecycle of user input submissions. Enhanced escape key handling to prioritize canceling pending optimistic submissions before aborting active sessions.
- Extracted loading animation lifecycle management into centralized ensureLoadingAnimation() method.
- Consolidated duplicate loading animation setup across event-controller and interactive-mode into single reusable method.
- Updated showError() to properly clean up loading animation state when errors occur.
- Added comprehensive test coverage for InputController escape key behavior with optimistic submission.