progress: modernize API with functional core and improved rendering
ocaml-tty:
- Add functional API (state, config, render) for pure state management
- Smooth gradient bar using partial block characters (▏▎▍▌▋▊▉█)
- ANSI color support (cyan spinner, green bar, dim counter)
- Add phase support for multi-step operations
- Add reset function to reuse progress bars across phases
- Make total required (no more indeterminate spinner mode)
monopam:
- Consolidate push into single progress bar for both phases
- Remove interleaved status messages (all printed at end)
- Use update() for cleaner progress loop