Reset multiple connection flags (content_type_checked, is_textual_content, response_headers_parsed, original_content_length, content_length_delta, patch_blocked) when reusing connection for internal route keep-alive. Add immediate handling of any buffered read data after state reset to prevent stale data blocking subsequent requests. Add comprehensive test verifying second request processing on internal dashboard route via Unix socket pair.
Add real-time tracking of accepted connections, upstream connection success/failure, DNS errors, and retries to connection.c. Introduce histogram, rate tracker, and health score data structures in types.h and monitor.h/c. Redesign dashboard HTML/CSS with color-coded health metrics, responsive charts grid, and tall chart containers for improved visualization of system performance data.
