feat: ticker search, watchlist momentum column, alpha vs S&P 500

Three usability fixes:

1. Global ticker search in the sidebar (TickerSearch) — typeahead over the
   tracked universe that opens a ticker's detail page without adding it to the
   watchlist. Also wired into the mobile nav.

2. Watchlist table shows the ticker's 12-1 momentum percentile (the top-pick
   selector) instead of the noisy full S/R-level list. Enriched from the setup
   already loaded in watchlist_service._enrich_entry — no extra query.

3. Alpha vs the S&P 500 on paper trades (open + closed). New benchmark_prices
   table + benchmark_service store SPY daily closes (a standalone series, not a
   Ticker, so it never enters the scanner / momentum ranking / rankings) via a
   new daily-pipeline step. paper_trade_service computes per-trade
   benchmark_return / alpha_pct / alpha_usd over each holding period; the open-
   trades table, dashboard, and closed-trades panel surface per-trade and total
   alpha. The list read path never makes a provider call.

Deploy: alembic upgrade head, then run the benchmark/daily job once to populate
SPY closes (alpha shows "—" until then).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/src/components/layout/MobileNav.tsx

@@ -1,6 +1,7 @@
 import { useState } from 'react';
 import { NavLink } from 'react-router-dom';
 import { useAuthStore } from '../../stores/authStore';
+import TickerSearch from './TickerSearch';
 
 const navItems = [
   { to: '/', label: 'Overview', end: true },
@@ -46,6 +47,9 @@ export default function MobileNav() {
         }`}
       >
         <nav className="px-3 py-2 space-y-1">
+          <div className="pb-2">
+            <TickerSearch onNavigate={() => setOpen(false)} />
+          </div>
           {navItems.map(({ to, label, end }) => (
             <NavLink
               key={to}

frontend/src/components/layout/Sidebar.tsx

@@ -3,6 +3,7 @@ import { useQuery } from '@tanstack/react-query';
 import { useAuthStore } from '../../stores/authStore';
 import { check as healthCheck } from '../../api/health';
 import { getRunningJobs } from '../../api/jobs';
+import TickerSearch from './TickerSearch';
 
 const navItems = [
   { to: '/', label: 'Overview', index: '01', end: true },
@@ -54,6 +55,10 @@ export default function Sidebar() {
         <p className="text-[10px] text-gray-500 mt-1.5 font-mono uppercase tracking-[0.22em]">Trading Intelligence</p>
       </div>
 
+      <div className="px-3 pt-4">
+        <TickerSearch />
+      </div>
+
       <nav className="flex-1 px-3 py-5 space-y-1">
         {navItems.map(({ to, label, index, end }) => (
           <NavLink key={to} to={to} end={end} className={({ isActive }) => linkClasses(isActive)}>

frontend/src/components/layout/TickerSearch.tsx

@@ -0,0 +1,96 @@
+import { useMemo, useRef, useState } from 'react';
+import { useNavigate } from 'react-router-dom';
+import { useTickers } from '../../hooks/useTickers';
+import { Input } from '../ui/Field';
+
+const MAX_RESULTS = 8;
+
+/** Jump-to-ticker search over the tracked universe. Selecting a match opens its
+ *  detail page — it does NOT add the ticker to the watchlist. */
+export default function TickerSearch({ onNavigate }: { onNavigate?: () => void }) {
+  const tickers = useTickers();
+  const navigate = useNavigate();
+  const [q, setQ] = useState('');
+  const [open, setOpen] = useState(false);
+  const [active, setActive] = useState(0);
+  const blurTimer = useRef<number | null>(null);
+
+  const matches = useMemo(() => {
+    const query = q.trim().toUpperCase();
+    if (!query) return [];
+    const all = tickers.data ?? [];
+    const starts = all.filter((t) => t.symbol.toUpperCase().startsWith(query));
+    const contains = all.filter(
+      (t) => !t.symbol.toUpperCase().startsWith(query) && t.symbol.toUpperCase().includes(query),
+    );
+    return [...starts, ...contains].slice(0, MAX_RESULTS);
+  }, [q, tickers.data]);
+
+  const go = (symbol: string) => {
+    navigate(`/ticker/${symbol}`);
+    setQ('');
+    setOpen(false);
+    setActive(0);
+    onNavigate?.();
+  };
+
+  const onKeyDown = (e: React.KeyboardEvent<HTMLInputElement>) => {
+    if (e.key === 'ArrowDown') {
+      e.preventDefault();
+      setActive((a) => Math.min(a + 1, matches.length - 1));
+    } else if (e.key === 'ArrowUp') {
+      e.preventDefault();
+      setActive((a) => Math.max(a - 1, 0));
+    } else if (e.key === 'Enter') {
+      e.preventDefault();
+      const m = matches[active];
+      if (m) go(m.symbol);
+    } else if (e.key === 'Escape') {
+      setQ('');
+      setOpen(false);
+    }
+  };
+
+  const showList = open && q.trim().length > 0 && matches.length > 0;
+
+  return (
+    <div className="relative">
+      <Input
+        type="text"
+        value={q}
+        onChange={(e) => {
+          setQ(e.target.value);
+          setOpen(true);
+          setActive(0);
+        }}
+        onFocus={() => setOpen(true)}
+        onBlur={() => {
+          blurTimer.current = window.setTimeout(() => setOpen(false), 120);
+        }}
+        onKeyDown={onKeyDown}
+        placeholder="Search ticker…"
+        aria-label="Search ticker"
+        autoComplete="off"
+        className="w-full"
+      />
+      {showList && (
+        <ul className="absolute z-20 mt-1 max-h-72 w-full overflow-y-auto rounded-lg glass py-1 shadow-xl">
+          {matches.map((t, i) => (
+            <li key={t.symbol}>
+              <button
+                type="button"
+                onMouseEnter={() => setActive(i)}
+                onClick={() => go(t.symbol)}
+                className={`flex w-full items-center px-3 py-1.5 text-left text-sm transition-colors ${
+                  i === active ? 'bg-blue-400/[0.12] text-blue-200' : 'text-gray-300 hover:bg-white/[0.04]'
+                }`}
+              >
+                {t.symbol}
+              </button>
+            </li>
+          ))}
+        </ul>
+      )}
+    </div>
+  );
+}