Feat/posthog error tracking redaction

[laxmanclo]

This improves telemetry without widening what we send remotely.

Renderer exceptions now go into PostHog Error Tracking(before it was just tracking the error, not capturing in depth, which gives us proper grouped UI issues. We also scrub local paths and local URLs before capture. On the backend, failures still emit as events, but now include better structured metadata like component, operation, error kind/code, and
fingerprints so they are easier to group and investigate without leaking raw internals. Backend tele can still be improved a lot, but requires lots of change.

[Vaibhaav-Tiwari]

Reviewed locally. I found one blocking privacy issue.

The PR claims local URLs are redacted before PostHog capture, but embedded local URLs inside
exception text are not redacted. For example, a message like:

failed to fetch http://127.0.0.1:3037/api/v1/projects?token=secret

would still be sent through unchanged. Same issue applies to embedded localhost and app:// renderer/... URLs. The current logic only handles file:///... when embedded, or local URLs when
the whole string is exactly the URL.

Local checks:

• Backend telemetry/http/session tests passed.
• Frontend typecheck passed.
• Frontend telemetry tests passed.
• Full frontend suite mostly passed; one unrelated NewTaskDialog test timed out at default 5s
  but passed when rerun with a longer timeout.

Recommendation: don’t merge yet. Please extend the redaction logic and tests for embedded
localhost, 127.0.0.1, [::1], and app://renderer URLs in exception messages/stack fields.