test(#351): pin the whole daily-only recovery end to end

Covers the chain in one place rather than in five separate unit tests:
the file parses to NaN at face value, #350's validation now rejects it,
#351 recovers the codes the file already contains, the raw_weather path
produces a fully finite series from them, and validation then passes
clean.

The fixture reproduces the SHAPE of vita's file — hourly observations at
:06 with the indices on the 19:06 row only. The four daily readings are
the exact values recorded in #351.

Verified against a running stack the same day: POST /models/preflight
returned FFMC 84.65, DMC 20.72, DC 424.90 from 2026-08-03, and the wizard
carried an accepted answer through to a real FireSTARR invocation with
--ffmc 84.5 --dmc 24 --dc 432.5 on the command line. Finite numbers where
the original failure had --ffmc NaN and exit 139.

693 tests, 75 files. tsc clean.

Author: spydmobile

backend/src/infrastructure/weather/__tests__/dailyOnlyRecovery.e2e.test.ts

@@ -0,0 +1,166 @@
+/**
+ * End-to-end recovery of a daily-only CFFDRS file — issues #350, #351.
+ *
+ * The failure this reproduces: a FireSTARR-format CSV recording its indices
+ * once a day parsed to NaN on every other row, those NaNs were written to
+ * weather.csv AND placed on the FireSTARR command line, and the engine died
+ * with SIGSEGV. vita hit it six times in a week on the CIFFC demo.
+ *
+ * The fixture reproduces the SHAPE of her file — hourly observations at :06
+ * with the indices on the 19:06 row only. The first four daily readings are the
+ * exact values recorded in #351; the rest continue the trend and are invented.
+ *
+ * This covers the whole recovery: detect the shape, recover the codes, run them
+ * through the raw_weather path, and confirm nothing non-finite survives.
+ */
+
+import { describe, it, expect } from 'vitest';
+import { WeatherService } from '../WeatherService.js';
+import { hasDailyOnlyCffdrs, findStartingCodeCandidate } from '../dailyCffdrs.js';
+import { validateWeatherData } from '../../firestarr/WeatherCSVWriter.js';
+
+const ZONE = 'America/Edmonton';
+const IGNITION = new Date('2026-08-04T18:00:00.000Z'); // 12:00 local
+
+const DAILY_READINGS: Record<string, [number, number, number]> = {
+  '2026-08-01': [81.66, 19.22, 412.67],
+  '2026-08-02': [76.3, 18.52, 418.6],
+  '2026-08-03': [84.65, 20.72, 424.9],
+  '2026-08-04': [88.44, 23.66, 432.05],
+};
+
+const TEMPS = [16.1, 15.4, 14.9, 14.5, 14.2, 15.0, 17.3, 19.8, 21.9, 23.4, 24.4, 25.1,
+  25.8, 26.3, 26.6, 26.4, 25.7, 24.8, 23.8, 22.1, 20.4, 19.0, 17.9, 16.9];
+const RHS = [72, 75, 78, 80, 82, 79, 70, 60, 52, 48, 46, 43, 41, 39, 38, 39, 43, 50, 61, 66, 69, 71, 72, 73];
+
+function vitaShapedCsv(): string {
+  const lines = ['Scenario,Date,PREC,TEMP,RH,WS,WD,FFMC,DMC,DC,ISI,BUI,FWI'];
+
+  for (const [day, [ffmc, dmc, dc]] of Object.entries(DAILY_READINGS)) {
+    for (let hour = 0; hour < 24; hour++) {
+      const stamp = `${day} ${String(hour).padStart(2, '0')}:06:00`;
+      const observation = `0,${stamp},0,${TEMPS[hour]},${RHS[hour]},8.0,222`;
+
+      lines.push(
+        hour === 19
+          ? `${observation.replace(',222', ',217')},${ffmc},${dmc},${dc},2,34.44,4.64`
+          : `${observation},NaN,NaN,NaN,NaN,NaN,NaN`,
+      );
+    }
+  }
+
+  return lines.join('\n');
+}
+
+const service = new WeatherService();
+
+describe("vita's file, end to end", () => {
+  it('parses to NaN when taken at face value — the original failure', async () => {
+    const points = await service.resolveWeather(
+      { source: 'firestarr_csv', firestarrCsvContent: vitaShapedCsv(), timezone: ZONE },
+      { latitude: 53.5, longitude: -113.5 },
+      { start: IGNITION, end: IGNITION },
+    );
+
+    // 92 of 96 rows carry no indices at all.
+    expect(points.some((p) => !Number.isFinite(p.ffmc))).toBe(true);
+  });
+
+  it('is now REJECTED by validation instead of reaching the engine (#350)', async () => {
+    const points = await service.resolveWeather(
+      { source: 'firestarr_csv', firestarrCsvContent: vitaShapedCsv(), timezone: ZONE },
+      { latitude: 53.5, longitude: -113.5 },
+      { start: IGNITION, end: IGNITION },
+    );
+
+    const result = validateWeatherData(
+      points.map((p) => ({
+        date: p.datetime,
+        temp: p.temperature,
+        rh: p.humidity,
+        ws: p.windSpeed,
+        wd: p.windDirection,
+        precip: p.precipitation,
+        ffmc: p.ffmc,
+        dmc: p.dmc,
+        dc: p.dc,
+        isi: p.isi ?? 0,
+        bui: p.bui ?? 0,
+        fwi: p.fwi ?? 0,
+      })) as Parameters<typeof validateWeatherData>[0],
+    );
+
+    expect(result.valid).toBe(false);
+  });
+
+  it('recovers the codes the file already contains (#351)', async () => {
+    const points = await service.resolveWeather(
+      { source: 'firestarr_csv', firestarrCsvContent: vitaShapedCsv(), timezone: ZONE },
+      { latitude: 53.5, longitude: -113.5 },
+      { start: IGNITION, end: IGNITION },
+    );
+
+    expect(hasDailyOnlyCffdrs(points)).toBe(true);
+
+    const candidate = findStartingCodeCandidate(points, IGNITION, ZONE);
+    expect(candidate).not.toBeNull();
+    expect([candidate!.ffmc, candidate!.dmc, candidate!.dc]).toEqual([84.65, 20.72, 424.9]);
+  });
+
+  it('produces a fully finite series once those codes are accepted', async () => {
+    // The payoff. Same file, raw_weather path, codes recovered from the file
+    // itself — every row now carries real numbers.
+    const points = await service.resolveWeather(
+      {
+        source: 'raw_weather',
+        rawWeatherContent: vitaShapedCsv(),
+        startingCodes: { ffmc: 84.65, dmc: 20.72, dc: 424.9 },
+        latitude: 53.5,
+        timezone: ZONE,
+      },
+      { latitude: 53.5, longitude: -113.5 },
+      { start: IGNITION, end: IGNITION },
+    );
+
+    expect(points.length).toBe(96);
+    for (const point of points) {
+      expect(Number.isFinite(point.ffmc)).toBe(true);
+      expect(Number.isFinite(point.dmc)).toBe(true);
+      expect(Number.isFinite(point.dc)).toBe(true);
+    }
+  });
+
+  it('passes the validation that used to let NaN through to the command line', async () => {
+    const points = await service.resolveWeather(
+      {
+        source: 'raw_weather',
+        rawWeatherContent: vitaShapedCsv(),
+        startingCodes: { ffmc: 84.65, dmc: 20.72, dc: 424.9 },
+        latitude: 53.5,
+        timezone: ZONE,
+      },
+      { latitude: 53.5, longitude: -113.5 },
+      { start: IGNITION, end: IGNITION },
+    );
+
+    const result = validateWeatherData(
+      points.map((p) => ({
+        date: p.datetime,
+        temp: p.temperature,
+        rh: p.humidity,
+        ws: p.windSpeed,
+        wd: p.windDirection,
+        precip: p.precipitation,
+        ffmc: p.ffmc,
+        dmc: p.dmc,
+        dc: p.dc,
+        isi: p.isi ?? 0,
+        bui: p.bui ?? 0,
+        fwi: p.fwi ?? 0,
+      })) as Parameters<typeof validateWeatherData>[0],
+    );
+
+    expect(result.issues).toEqual([]);
+    expect(result.valid).toBe(true);
+  });
+});