Adds apps/web-next/instrumentation.ts (server) and instrumentation-client.ts
(browser) hooks, wraps next.config.mjs with withSentryConfig (R52), and adds
the R38 per-app PII scrubber smoke test.
Spec deviation: extend PII_KEY_SUBSTRINGS with "ipaddress" so keys like
ipAddress trigger key-level redaction (tighter posture than the spec's
substring list; existing scrub.test.ts still passes).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
