chore: merged in upstream changes

- Added ExtensionRuntime shared state with async extension factory support
- Introduced pluggable tool operations (BashOperations, FileOperations, etc.) for remote execution
- Added new CLI flags: --no-tools, --no-extensions, --no-skills
- Added login dialog, countdown timer, and component barrel export
- Added blockImages and thinkingBudgets settings
- Refactored stdin handling with StdinBuffer for improved key parsing
- Updated DEVELOPMENT.md with new architecture documentation

.gitignore

@@ -39,3 +39,5 @@ out.html
 .claude/*
 !.claude/commands/
 packages/ai/test/.temp-images/
+
+changes/