Milestones 0 and 1: foundation and money in (20261007.10)

Foundation: single arm64 container (Hono + SQLite via Drizzle, React + Vite),
local sign-in with long-lived sessions and passkeys, roles (read-only, full
access, admin), nightly and pre-upgrade backups, light and dark themes,
date-based version numbers, and the ideas lightbulb behind IDEAS_ENABLED.

Money in: accounts with balances, CSV import with bank detection, a column
mapping pop-up for unknown layouts, duplicate checks, transfer pairing and
undo; one-tap review with learned rules; activity with search, splits, tags,
notes and cash entries. Statement files are blocked from commits by a
pre-commit hook; tests use synthetic fixtures only.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

web/src/components/RouteError.tsx

@@ -0,0 +1,25 @@
+import { RefreshCw, TriangleAlert } from 'lucide-react';
+import { useRouteError } from 'react-router';
+import { Button } from './ui/button';
+
+/** Shown instead of a blank screen if something breaks while drawing a page. */
+export function RouteError() {
+  const error = useRouteError();
+  if (error) console.error(error);
+  return (
+    <div className="flex min-h-[60dvh] items-center justify-center px-4 py-16">
+      <div className="max-w-sm text-center">
+        <span className="mx-auto mb-5 flex size-14 items-center justify-center rounded-2xl bg-warn/12 text-warn">
+          <TriangleAlert className="size-7" strokeWidth={1.8} />
+        </span>
+        <h2 className="text-xl font-semibold tracking-tight">Something went wrong</h2>
+        <p className="mt-2 text-[14.5px] leading-relaxed text-muted-foreground">
+          This screen hit a problem. Reloading usually fixes it, and nothing you saved has been lost.
+        </p>
+        <Button className="mt-6" onClick={() => window.location.reload()}>
+          <RefreshCw /> Reload
+        </Button>
+      </div>
+    </div>
+  );
+}