Increase long-poll fallback timeout to 5s for mobile networks, add
visibility change listener for proper reconnection on app foreground,
and remove backdrop blur that stalls network operations on iOS Safari.
Convert app.js, info_map.js, error_boundary.js, and time_ago_hook.js
to TypeScript with proper typing for Phoenix hooks, Leaflet, DOM
interactions, and timer management. Update esbuild hex package to
~> 0.10 and binary to 0.25.4. Entry point changed to app.ts.
