- Add CommandAutocomplete component with filtered command list, aliases, arg hints - Add useInputHistory hook with ring buffer (max 50), up/down navigation, saved input restore - Wire InputBar with autocomplete state (show on /), Tab/Enter to fill, Escape to dismiss - Wire up/down arrows: autocomplete navigation when open, history navigation when closed - Pass allCommands prop from app.tsx commandRegistry to InputBar - Add 8 pure-logic tests for useInputHistory covering edge cases and caps Co-Authored-By: Claude Sonnet 4.6 <[email protected]>