Introduce a telemetry module that exposes a `reportError` helper.
Under the hood it forwards errors to PostHog, but the module is the
only place that knows about PostHog.
Replace `console.error` calls used for error reporting with
`reportError`, so the codebase now goes through a single, consistent
API for telemetry.
This normalizes how errors are reported and makes it straightforward
to swap PostHog for another backend later on, without touching every
call site.
Mark JS imports as type-only when applicable so they are stripped at
build time and ignored during chunk splitting, ensuring we take full
advantage of Rollup's code-splitting optimizations.