Merge C19: adaptive triple-barrier labeling into old_wang_dev

Merge HF artifact commits; keep login-removal codebase

Remove entire login/auth system; anonymous localStorage favorites

Remove Google login from frontend

Improve dashboard latency caching

Backup current stock predictor strategies

Merge remote-tracking branch 'hf/main' into codex/self-refine-validation-gate

feat: integrate local architecture with HF Space

Clarify prediction reliability display

Clarify watchlist quick estimates

Fix HF queue prediction placeholders

fix: HF Space always returns Mac ML result on first call

feat: quick-estimate + background ML + auto-poll

feat: add Market Scan recommendation dashboard

feat: add chip_score, MA120/240, margin flow, and TA distillation

feat: add 三大法人 buy/sell/net table and dealer_net line to institutional chart

feat: add institutional signals and HF-friendly deploy

feat: add Recent 1-2 Month Overview chart with stats

feat(metal): Phase 2 frontend — MetalDashboard + charts + prediction

feat: comprehensive optimization — 30 improvements across ML, perf, frontend, security, architecture

feat: walk-forward backtest, US currency, mobile RWD, Gemini news summary

feat: realtime quote (twstock + yfinance), today change %, 30s auto-refresh

feat: restore BacktestPanel — historical backtest UI recovered from git history

refactor: improve ML features, LINE Flex Messages, watchlist panel, health endpoint

feat: market tabs (台股/美股/基金), autocomplete search, favorites filter tabs