feat: FF→FRED series mapping + MacroSeries visualization page

Backend:
- ff_calendar: add series_id column (migration) + FF_TO_FRED mapping dict
  (NFP→PAYEMS, CPI→CPIAUCSL, Jobless Claims→ICSA, GDP→GDPC1, FEDFUNDS, PCE)
- import_csv + sync_live now populate series_id on each FF event
- New GET /api/eco/series/{id}/history: FRED time series + linked FF events
  (surprises, forecast, actual) merged by date — enables context queries

Frontend:
- New MacroSeriesPage.tsx: sidebar with 11 FRED series grouped by category,
  recharts ComposedChart with area + z-score surprise reference lines (|z|≥1.5),
  KPI cards (latest/prev/min/max), FF events table (actual vs forecast coloring),
  z-score bar chart for recent surprises, range selector (1Y/2Y/5Y/10Y/All)
- Route /macro-series + Sidebar entry "Macro Series"

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

frontend/src/App.tsx

@@ -28,6 +28,7 @@ import InstrumentDashboard from './pages/InstrumentDashboard'
 import CycleActions from './pages/CycleActions'
 import MarketEvents from './pages/MarketEvents'
 import AIDesks from './pages/AIDesks'
+import MacroSeriesPage from './pages/MacroSeriesPage'
 import { Navigate } from 'react-router-dom'
 import { useCycleWatcher } from './hooks/useApi'
 
@@ -55,6 +56,7 @@ export default function App() {
             <Route path="/portfolio" element={<Portfolio />} />
             <Route path="/backtest" element={<Backtest />} />
             <Route path="/calendar" element={<CalendarPage />} />
+            <Route path="/macro-series" element={<MacroSeriesPage />} />
             <Route path="/journal" element={<JournalDeBord />} />
             <Route path="/rapport" element={<RapportIA />} />
             <Route path="/super-contexte" element={<SuperContexte />} />