feat(web-next): Sentry instrumentation hooks + withSentryConfig + R38 PII test

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>

packages/core-shared/package.json

@@ -9,7 +9,10 @@
     "./trpc/init": "./src/trpc/init.ts",
     "./trpc/context": "./src/trpc/context.ts",
     "./trpc/define-error-middleware": "./src/trpc/define-error-middleware.ts",
-    "./instrumentation": "./src/instrumentation/index.ts"
+    "./instrumentation": "./src/instrumentation/index.ts",
+    "./instrumentation/sentry/init-server": "./src/instrumentation/sentry/init-server.ts",
+    "./instrumentation/sentry/init-client": "./src/instrumentation/sentry/init-client.ts",
+    "./instrumentation/sentry/scrub": "./src/instrumentation/sentry/scrub.ts"
   },
   "scripts": {
     "build": "tsc --noEmit",