Add settings page for managing forecasting API key and URL via UI

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

frontend/node_modules/caniuse-lite/dist/lib/statuses.js

@@ -0,0 +1,9 @@
+module.exports = {
+  1: 'ls', // WHATWG Living Standard
+  2: 'rec', // W3C Recommendation
+  3: 'pr', // W3C Proposed Recommendation
+  4: 'cr', // W3C Candidate Recommendation
+  5: 'wd', // W3C Working Draft
+  6: 'other', // Non-W3C, but reputable
+  7: 'unoff' // Unofficial, Editor's Draft or W3C "Note"
+}