fix: make sentry optional

[hanneshapke]

Description

This PR makes the telemetry reporting opt-in

Linked Issue

Closes #

Testing Done

Still ongoing

Unit tests (Go):

make test-go

Unit tests (Python):

make test

Linting & type checks:

make lint
make typecheck

Manual testing (if applicable):

• Describe the scenario tested (e.g. PII type detected, proxy request flow, Chrome extension behavior)
• Include before/after behavior if fixing a bug
• Note any edge cases verified (e.g. nested PII in JSON payloads, restoration accuracy)

Checklist

• make test-go and make test pass locally
• make lint reports no new errors
• New PII detection changes are covered by unit tests in tests/
• Go proxy changes include test coverage in src/ or model/
• Documentation updated if behavior or configuration changed
• No sensitive data or credentials included