feat: align candidate relevance ranking & implement robust Turbo Mode fallback

Fix remote candidate search returning 0 results by mapping preferred_work_mode

fix: app.py scoping error + new Sage+Terracotta theme

feat: complete UI redesign with pastel purple/orange theme

UI: zero gradients, peaceful warm palette, borders for elevation

UI redesign: pastel theme, premium card design, progressive loading

feat: final smoke-test fixes + spectacular README + UI bugfixes

Overhaul: Plackett-Luce ranking, PII anonymization, live fairness dashboard + LLM-free fallback agents

feat: Phase 11 Gradio UI — search tab, analytics dashboard, about page