fix: backfill symbol_demand for sidebar-added symbols + analyst ratings schema fix

- Add await ctx.cache.subscribe() to addSymbol mutation so symbols
  added via the sidebar get registered in symbol_demand and yfinance
  jobs are queued immediately
- Backfill PEP, WYNN, STZ, CELH into symbol_demand + adapter_queue
- Upgrade yahoo-finance2 3.15.3 -> 3.15.4 and pass validateResult:false
  to quoteSummary() to handle Yahoo schema drift
- Add error detail logging for analyst ratings schema failures
- Update .gitignore with common ignores

app/server/src/analysis/__tests__/seasonality.test.ts

@@ -0,0 +1,69 @@
+import { test } from 'node:test';
+import { strict as assert } from 'node:assert';
+import {
+  monthlyReturnsFromCandles,
+  aggregateMonthSeasonality,
+  buildSeasonalitySnapshot,
+  electionCycleYear,
+  upcomingSimpleEvents,
+} from '../seasonality.ts';
+
+function mkYear(year: number, monthlyCloses: number[]) {
+  // One candle per month end-ish
+  return monthlyCloses.map((c, i) => ({
+    ts: new Date(Date.UTC(year, i, 28)).toISOString(),
+    c,
+  }));
+}
+
+test('monthlyReturnsFromCandles skips incomplete current month', () => {
+  // Use fixed "now" via candles only in past years
+  const candles = [
+    ...mkYear(2020, [100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111]),
+    ...mkYear(2021, [111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122]),
+  ];
+  const monthly = monthlyReturnsFromCandles(candles, new Date(Date.UTC(2026, 0, 15)));
+  assert.ok(monthly.length >= 20);
+  assert.ok(monthly.every((m) => Number.isFinite(m.returnPct)));
+});
+
+test('aggregateMonthSeasonality has 12 months', () => {
+  const monthly = [
+    { year: 2020, month: 1, returnPct: 2 },
+    { year: 2021, month: 1, returnPct: -1 },
+    { year: 2020, month: 5, returnPct: -3 },
+  ];
+  const agg = aggregateMonthSeasonality(monthly);
+  assert.equal(agg.length, 12);
+  assert.equal(agg[0].sampleYears, 2);
+  assert.ok(Math.abs(agg[0].avgReturnPct - 0.5) < 0.01);
+  assert.equal(agg[0].winRate, 0.5);
+});
+
+test('electionCycleYear labels 2026 as midterm year', () => {
+  const c = electionCycleYear(2026);
+  assert.equal(c.yearInCycle, 2);
+  assert.ok(/midterm/i.test(c.label));
+});
+
+test('buildSeasonalitySnapshot marks current month', () => {
+  const candles = [
+    ...mkYear(2019, Array.from({ length: 12 }, (_, i) => 100 + i)),
+    ...mkYear(2020, Array.from({ length: 12 }, (_, i) => 110 + i)),
+    ...mkYear(2021, Array.from({ length: 12 }, (_, i) => 120 + i)),
+  ];
+  const snap = buildSeasonalitySnapshot('SPY', candles, new Date(Date.UTC(2026, 6, 15)));
+  assert.equal(snap.currentMonth, 7);
+  assert.equal(snap.symbol, 'SPY');
+  assert.ok(snap.months.length === 12);
+  assert.ok(snap.electionCycle.label.length > 0);
+});
+
+test('upcomingSimpleEvents uses plain language', () => {
+  const events = upcomingSimpleEvents();
+  assert.ok(events.length >= 3);
+  for (const e of events) {
+    assert.ok(e.plainWhy.length > 20);
+    assert.ok(!/you should buy|go long/i.test(e.plainWhy));
+  }
+});