fix(frontend): perf + SystemNotice correctness (phase 6a)

feat(chat): consume the SSE stream — proxy pipe, incremental parser, bounded-lag reveal (#81)

fix(frontend): render card chips for backticked card names in answers (#67)

feat(chat): surface request failures as a system notice, not a judge reply

feat(chat): render Reasoning/Answer as section eyebrows

fix: elimina disclaimer falso de no-info y actualiza tip de ejemplo

fix(frontend): elimina marcadores de cita inline del texto de respuesta

feat(frontend): light/dark theme toggle con tokens de marca

feat(frontend): render rb_* symbol icons, keyword tooltips, tolerant card detection

feat(frontend): highlight multi-word card names in judge answers

feat(chat): replace inline sources with popup and add rule reference links

feat(ui): add keyword badges with skewed style in answer display

feat(hardening): frontend error states -- typed errors + ErrorDisplay component

feat: add components, pages, and tests for frontend MVP