Add status bar and compact summary widgets with context window resolu… (#152)

* Add status bar and compact summary widgets with context window resolution

- Implemented a shared status bar for CLI and TUI frontends, including helpers for managing session metrics and context windows.
- Created a `CompactSummaryWidget` for displaying manual summaries in a collapsible format.
- Introduced a `CompactingWidget` to indicate ongoing compacting processes.
- Added a base class `TimedStatusWidget` for widgets that require a timer.
- Developed context window resolution helpers to retrieve context window sizes from various model attributes.
- Enhanced tests for context window resolution and status bar functionalities, ensuring accurate behavior across different scenarios.
- Updated existing tests to cover new features and maintain code quality.

* refactor(Channel): simplify lambda function in _send_with_retry method

* feat: enhance context editing logic and improve error handling in StreamState

* refactor(Channel): streamline lambda function in _send_with_retry method

* feat: rename auto-approve option to auto-mode for unattended execution; update checkpoint queries to filter by agent name; improve compatibility validation logic

* feat: rename auto-approve option to auto-mode; update related logic and tests for improved unattended execution

* fix: correct formatting of console message for MCP server configuration status

* feat: add check for None summary_message in _apply_summarization_event to prevent errors

* feat: enhance _load_checkpoint_messages to validate message format and apply summarization event

EvoScientist/stream/emitter.py

@@ -181,6 +181,14 @@ class StreamEventEmitter:
             "summarization", {"type": "summarization", "content": content}
         )
 
+    @staticmethod
+    def summarization_start() -> StreamEvent:
+        """Context summarization started."""
+        return StreamEvent(
+            "summarization_start",
+            {"type": "summarization_start"},
+        )
+
     @staticmethod
     def error(message: str) -> StreamEvent:
         """Error event."""