feat(telemetry): report uncaught errors

[PhilippTheServer]

Closes #4 · consumes OpenTaberna/fastapi#51

An error that breaks checkout was visible only in the console of the person it happened to.
A global ErrorHandler now reports uncaught errors to the API — off by default, like the
analytics port.

A render loop must not become a request loop

The failure mode being reported on is a component throwing during render, which calls the
handler as fast as the browser can loop. So:

• an identical error is reported at most 3 times per session
• a hard 50-per-session ceiling regardless of how many distinct errors
• reports are batched, and a failing endpoint is swallowed

A reporter that turns a render loop into a request loop takes a broken page and makes it a
broken page plus a hammered API.

Anything can be thrown in JavaScript

And frameworks do. Nothing assumes an Error shape — strings, bare objects and null all
produce a usable report rather than an exception raised inside the error handler, which
would be a genuinely bad place to throw.

It still logs to the console

Swallowing that would remove what a developer looks at first, in exchange for a report they
cannot see locally. And if the reporter itself throws, that is caught, so it can never mask
the original error.

Verification

$ npx ng test --watch=false
 Test Files  2 passed (2)
      Tests  23 passed (23)

$ npx ng build
Initial total | 330.11 kB | 89.60 kB

Twelve new tests, each pinning a way this could make things worse: 500 identical throws
produce 3 reports; 100 distinct errors stop at the ceiling; a thrown string, a bare object
and null are all handled; the query string is stripped from the reported path; a failing
endpoint does not throw; the console still receives the error; and a reporter that throws
does not mask it.