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>

packages/core-eslint/base.js

@@ -3,10 +3,17 @@ import eslintConfigPrettier from "eslint-config-prettier";
 import tseslint from "typescript-eslint";
 import turboPlugin from "eslint-plugin-turbo";
 import boundaries from "eslint-plugin-boundaries";
+import globals from "globals";
 
 export default [
   { ignores: ["dist/**", "node_modules/**", ".next/**", ".turbo/**", "storybook-static/**"] },
   js.configs.recommended,
+  {
+    files: ["**/*.{mjs,cjs,js}", "**/*.config.{ts,tsx}"],
+    languageOptions: {
+      globals: { ...globals.node },
+    },
+  },
   ...tseslint.configs.recommended,
   eslintConfigPrettier,
   {
@@ -15,6 +22,19 @@ export default [
       "turbo/no-undeclared-env-vars": "warn",
     },
   },
+  {
+    rules: {
+      // Honour the leading-underscore convention for intentionally-unused params/vars.
+      "@typescript-eslint/no-unused-vars": [
+        "error",
+        {
+          argsIgnorePattern: "^_",
+          varsIgnorePattern: "^_",
+          caughtErrorsIgnorePattern: "^_",
+        },
+      ],
+    },
+  },
   {
     plugins: { boundaries },
     settings: {
@@ -45,4 +65,42 @@ export default [
       ],
     },
   },
+  // R40 — block direct @sentry/* imports outside the allowlisted instrumentation paths
+  {
+    files: ["**/*.{ts,tsx,mjs,cjs,js}"],
+    rules: {
+      "no-restricted-imports": [
+        "error",
+        {
+          patterns: [
+            {
+              group: ["@sentry/*"],
+              message:
+                "Import from @repo/core-shared/instrumentation instead — feature packages must not depend on Sentry directly (R40).",
+            },
+          ],
+        },
+      ],
+    },
+  },
+  // R40 allowlist — the only paths permitted to import @sentry/*.
+  // Patterns are double-star prefixed so they match whether eslint runs from
+  // the repo root or from inside a sub-package.
+  {
+    files: [
+      "**/instrumentation/sentry/**",
+      "**/instrumentation/di/bind-sentry-instrumentation.{ts,js}",
+      "**/instrumentation/di/bind-sentry-instrumentation.test.{ts,js}",
+      "**/setup/no-sentry.{ts,js}",
+      "**/setup/no-sentry.test.{ts,js}",
+      "**/instrumentation.{ts,js,mjs}",
+      "**/instrumentation-client.{ts,js,mjs}",
+      "**/next.config.{mjs,ts,js}",
+      "**/vite.config.{ts,mjs,js}",
+      "**/sentry.*.config.{ts,mjs,js}",
+    ],
+    rules: {
+      "no-restricted-imports": "off",
+    },
+  },
 ];

packages/core-eslint/package.json

@@ -17,5 +17,8 @@
     "eslint-plugin-boundaries": "^4.2.2",
     "eslint-plugin-turbo": "^2.4.0",
     "typescript-eslint": "^8.25.0"
+  },
+  "dependencies": {
+    "globals": "^17.6.0"
   }
 }