fix: resolve ESLint circular structure crash and tsc OOM

- Replace FlatCompat bridge with native flat config imports from
  eslint-config-next (16.x exports flat configs directly)
- Remove unused @eslint/eslintrc devDependency
- Increase tsc heap to 4096MB for typecheck (55+ collections exceed 2GB)
- Exclude migrations, test artifacts from tsconfig type-checking

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

eslint.config.mjs

@@ -1,16 +1,9 @@
-import { dirname } from 'path'
+import coreWebVitals from 'eslint-config-next/core-web-vitals'
-import { fileURLToPath } from 'url'
+import typescript from 'eslint-config-next/typescript'
-import { FlatCompat } from '@eslint/eslintrc'
-
-const __filename = fileURLToPath(import.meta.url)
-const __dirname = dirname(__filename)
-
-const compat = new FlatCompat({
-  baseDirectory: __dirname,
-})
 
 const eslintConfig = [
-  ...compat.extends('next/core-web-vitals', 'next/typescript'),
+  ...coreWebVitals,
+  ...typescript,
   {
     rules: {
       '@typescript-eslint/ban-ts-comment': 'warn',

package.json

@@ -12,7 +12,7 @@
     "generate:types": "cross-env NODE_OPTIONS=--no-deprecation payload generate:types",
     "lint": "cross-env NODE_OPTIONS=--no-deprecation eslint src",
     "check:frameworks": "bash ./scripts/check-framework-updates.sh",
-    "typecheck": "cross-env NODE_OPTIONS=--no-deprecation tsc --noEmit",
+    "typecheck": "cross-env NODE_OPTIONS=\"--no-deprecation --max-old-space-size=4096\" tsc --noEmit",
     "format:check": "prettier --check \"src/**/*.{ts,tsx,js,jsx}\" --ignore-unknown",
     "format": "prettier --write \"src/**/*.{ts,tsx,js,jsx}\" --ignore-unknown",
     "payload": "cross-env NODE_OPTIONS=--no-deprecation payload",
@@ -58,7 +58,6 @@
     "sharp": "0.34.5"
   },
   "devDependencies": {
-    "@eslint/eslintrc": "^3.3.3",
     "@playwright/test": "1.57.0",
     "@types/node": "^22.10.2",
     "@types/node-cron": "^3.0.11",

pnpm-lock.yaml

@@ -96,9 +96,6 @@ importers:
         specifier: 0.34.5
         version: 0.34.5
     devDependencies:
-      '@eslint/eslintrc':
-        specifier: ^3.3.3
-        version: 3.3.3
       '@playwright/test':
         specifier: 1.57.0
         version: 1.57.0

tsconfig.json

@@ -40,6 +40,11 @@
     ".next/dev/types/**/*.ts"
   ],
   "exclude": [
-    "node_modules"
+    "node_modules",
+    "src/migrations",
+    "src/migrations_backup",
+    "test-results",
+    "playwright-report",
+    "coverage"
   ]
 }