feat: Phase 1 — IV Rank, Term Structure, Skew, Options Flow (Sprint 1.1/1.2/1.3)

Backend:
- iv_engine.py: ATM IV, term structure (30/60/90/180j), put/call skew,
  options flow (P/C OI ratio, unusual strikes, gamma bias), proxy map for futures→ETFs
- database.py: iv_history table + save_iv_snapshot, get_iv_rank_percentile, get_iv_history
- routers/options_vol.py: /api/options-vol/ endpoints (snapshot, batch, watchlist, history)
- auto_cycle.py: inject IV context string into scoring prompt (step 3.5)
- ai_analyzer.py: score_patterns_with_context accepts iv_context param
- main.py: register options_vol router

Frontend:
- pages/OptionsLab.tsx: full IV dashboard (watchlist by IVR, term structure, skew, flow, sparkline)
- pages/JournalDeBord.tsx: IvRankCell component + IV Rank column per trade
- hooks/useApi.ts: useIvSnapshot, useIvWatchlist, useIvBatch, useIvHistory, useIvForTrade

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/hooks/useApi.ts

@@ -573,3 +573,43 @@ export const useDeleteKbEntry = () => {
     onSuccess: () => qc.invalidateQueries({ queryKey: ['knowledge-entries'] }),
   })
 }
+
+// ── Options Volatility ────────────────────────────────────────────────────────
+export const useIvSnapshot = (ticker: string) =>
+  useQuery({
+    queryKey: ['iv-snapshot', ticker],
+    queryFn: () => api.get(`/options-vol/snapshot/${encodeURIComponent(ticker)}`).then(r => r.data),
+    enabled: !!ticker,
+    staleTime: 60 * 60_000, // 1h — IV doesn't change that fast
+  })
+
+export const useIvWatchlist = () =>
+  useQuery({
+    queryKey: ['iv-watchlist'],
+    queryFn: () => api.get('/options-vol/watchlist').then(r => r.data),
+    staleTime: 60 * 60_000,
+  })
+
+export const useIvBatch = (tickers: string) =>
+  useQuery({
+    queryKey: ['iv-batch', tickers],
+    queryFn: () => api.get('/options-vol/batch', { params: { tickers } }).then(r => r.data),
+    enabled: !!tickers,
+    staleTime: 60 * 60_000,
+  })
+
+export const useIvHistory = (ticker: string, days = 90) =>
+  useQuery({
+    queryKey: ['iv-history', ticker, days],
+    queryFn: () => api.get(`/options-vol/history/${encodeURIComponent(ticker)}`, { params: { days } }).then(r => r.data),
+    enabled: !!ticker,
+    staleTime: 60 * 60_000,
+  })
+
+export const useIvForTrade = (underlying: string) =>
+  useQuery({
+    queryKey: ['iv-for-trade', underlying],
+    queryFn: () => api.get(`/options-vol/for-trade/${encodeURIComponent(underlying)}`).then(r => r.data),
+    enabled: !!underlying,
+    staleTime: 60 * 60_000,
+  })