Add Ambient Weather personal station integration

* Add Ambient Weather personal station integration

Fetches live data from the user's Ambient Weather station via their
REST API and displays it as a "My Station" card in the conditions tab.

- server.js: add /api/ambient endpoint with 60s cache using
  AMBIENT_API_KEY and AMBIENT_APP_KEY env vars
- docker-compose.yml: expose AMBIENT_API_KEY/AMBIENT_APP_KEY env vars
- index.html: add collapsible "My Station" drawer to conditions tab
  showing temp, humidity, wind, gusts, daily rain, pressure, UV,
  solar radiation, and indoor readings
- app.js: add fetchAmbientStation() and renderAmbientStation(),
  auto-refresh every 60s, peek text summary in drawer header
- style.css: station drawer styles
- .gitignore: add .env so API keys stay off git

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

* Move Ambient Weather keys to Settings panel

Users can now enter their API Key and Application Key directly in the
Settings tab under "Ambient Weather Station". Keys are saved to
localStorage and sent per-request to the server proxy.

- index.html: add API Key + Application Key inputs with Save button
- app.js: persist keys in localStorage, populate inputs on load,
  wire Save button (validates by testing the connection), pass keys
  as query params in fetchAmbientStation and its auto-refresh loop
- server.js: accept apiKey/appKey from query params with env var
  fallback; cache keyed per-user so multiple callers don't collide

---------

Co-authored-by: Claude <noreply@anthropic.com>

app/server.js

@@ -440,6 +440,30 @@ app.get('/api/spc/reports', async (_req, res) => {
   }
 });
 
+// ── Ambient Weather personal station ─────────────────────────────────────────
+const ambientCaches = new Map(); // keyed by apiKey so each user's cache is independent
+app.get('/api/ambient', async (req, res) => {
+  const apiKey = req.query.apiKey || process.env.AMBIENT_API_KEY;
+  const appKey = req.query.appKey || process.env.AMBIENT_APP_KEY;
+  if (!apiKey || !appKey) return res.status(503).json({ error: 'Ambient Weather keys not configured' });
+
+  const cacheKey = apiKey;
+  const cached = ambientCaches.get(cacheKey);
+  if (cached && Date.now() - cached.at < 60 * 1000) return res.json(cached.data);
+
+  try {
+    const url = `https://rt.ambientweather.net/v1/devices?apiKey=${encodeURIComponent(apiKey)}&applicationKey=${encodeURIComponent(appKey)}`;
+    const r = await fetchWithRetry(url, { attempts: 2, timeoutMs: 10000, retryDelayMs: 500 });
+    const devices = await r.json();
+    ambientCaches.set(cacheKey, { data: devices, at: Date.now() });
+    res.json(devices);
+  } catch (e) {
+    console.error('Ambient Weather fetch error:', e.message);
+    if (cached) return res.json(cached.data);
+    res.status(502).json({ error: 'Ambient Weather fetch failed' });
+  }
+});
+
 // ── Personal weather station proxy ────────────────────────────────────────────
 app.get('/api/pws', async (req, res) => {
   const { url } = req.query;