feat(eslint+ci): R40 boundary rule for @sentry/* + R31 sendDefaultPii grep gate

Adds two flat-config blocks to core-eslint/base.js: (1) repo-wide
no-restricted-imports for @sentry/* with the R40 message, (2) an
allowlist override for the only paths permitted to import the Sentry
SDK directly — core-shared/instrumentation/sentry/**, the bind-sentry
DI files, the no-sentry test guards, and apps' instrumentation* /
next.config / vite.config / sentry.*.config files. Patterns use
**/-prefix so they match whether ESLint runs from the repo root or
from inside a sub-package.

Also adds the standard `argsIgnorePattern: "^_"` config (used
throughout the repo) and a Node-globals override for *.mjs/*.cjs/*.js
and *.config.{ts,tsx} so withSentryConfig in next.config.mjs lints
clean. Required adding `globals` as a core-eslint dep.

Adds .github/workflows/sentry-pii-guard.yml — a lightweight CI step
that fails any PR introducing `sendDefaultPii: true` (R31). Excludes
node_modules / dist / .next / .turbo from the grep so vendored SDK
JSDoc examples don't false-positive.

Pre-existing lint nits cleared as part of getting `pnpm lint` green:
- core-testing define-contract-suite.test.ts: void the unused
  receivedTracer (mirrors the next test's pattern)
- marketing-pages bind-dev-seed.ts: drop unused MockSiteSettingsRepository
  import
- marketing-pages get-site-settings.use-case.ts: drop the now-redundant
  eslint-disable for `_input`

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

pnpm-lock.yaml

@@ -480,6 +480,10 @@ importers:
         version: 3.2.4(@types/debug@4.1.13)(@types/node@22.19.17)(happy-dom@20.8.9)(jiti@2.6.1)(jsdom@25.0.1)(lightningcss@1.32.0)(sass@1.99.0)(terser@5.46.2)(tsx@4.21.0)
 
   packages/core-eslint:
+    dependencies:
+      globals:
+        specifier: ^17.6.0
+        version: 17.6.0
     devDependencies:
       '@eslint/js':
         specifier: ^9.20.0
@@ -4956,6 +4960,10 @@ packages:
     resolution: {integrity: sha512-oahGvuMGQlPw/ivIYBjVSrWAfWLBeku5tpPE2fOPLi+WHffIWbuh2tCjhyQhTBPMf5E9jDEH4FOmTYgYwbKwtQ==}
     engines: {node: '>=18'}
 
+  globals@17.6.0:
+    resolution: {integrity: sha512-sepffkT8stwnIYbsMBpoCHJuJM5l98FUF2AnE07hfvE0m/qp3R586hw4jF4uadbhvg1ooIdzuu7CsfD2jzCaNA==}
+    engines: {node: '>=18'}
+
   gopd@1.2.0:
     resolution: {integrity: sha512-ZUKRh6/kUFoAiTAtTYPZJ3hw9wNxx+BIBOijnlG9PnrJsCcSjs1wyyD6vJpaYtgnzDrKYRSqf3OO6Rfa93xsRg==}
     engines: {node: '>= 0.4'}
@@ -11864,6 +11872,8 @@ snapshots:
 
   globals@14.0.0: {}
 
+  globals@17.6.0: {}
+
   gopd@1.2.0: {}
 
   graceful-fs@4.2.11: {}