This commit deletes the complete implementation of the agent loop, authentication module, web browsing utilities, chat prompt builder, database helper, and HTTP client. All corresponding header files and test harnesses are also removed. The diff shows the deletion of 6 source files and 6 header files totaling over 1000 lines of code, including the agent state machine, API key resolution logic, curl-based HTTP functions, SQLite database initialization and CRUD operations, and the JSON chat prompt construction.
Implement context manager integration that detects API errors indicating context length exceeded, then automatically shrinks message history and retries the request. Add new messages API functions (remove_range, get_object, replace_at) and a new R_ERROR_CONTEXT_TOO_LONG error code to support this functionality.
