This change modernizes the CopilotChat architecture by implementing a tools-based approach using function calling. Each tool has a schema definition that enables structured parameter collection and validation. Resources are now handled more consistently, with a clearer distinction between content types. https://platform.openai.com/docs/guides/function-calling?api-mode=responses https://modelcontextprotocol.info/specification/2024-11-05/server/tools/ BREAKING CHANGE: The context API has changed from callback-based input handling to schema-based definitions. BREAKING CHANGE: config.contexts renamed to config.tools BREAKING CHANGE: config.context removed, use config.sticky BREAKING CHANGE: diagnostics moved to separate tool call, selection and buffer calls no longer include them by default BREAKING CHANGE: non-resource based tool calls can no longer be soft stored in sticky, now they are auto expanded to promot BREAKING CHANGE: viewing full context is no longer possible (as now tools can have bigger side effects), gi renamed to gc, now also includes selection BREAKING CHANGE: filenames renamed to glob BREAKING CHANGE: files removed (use glob together with tool calling instead, or buffers/quickfix) BREAKING CHANGE: copilot extension agents removed, tools + mcp servers can replace this feature and maintaining them was pain, they can still be implemented via custom providers anyway BREAKING CHANGE: actions and integrations action removed as they were deprecated for a while Closes #1045 Closes #1053 Closes #1076 Closes #1090 Closes #1096 Closes #526 Signed-off-by: Tomas Slusny <slusnucky@gmail.com>