fix: 2026-06-09 full-codebase audit hardening

Validation: shared NaN-guarded Zod coercion helpers in schemas/common.ts replace
the raw number|string transform idiom across every schema (the root-cause NaN bug
class); emailOrEmpty + lenient isoDateString/timeString.

Security: roles privilege-escalation closed; refresh-token family revocation on
reuse; TOTP uses config params; read endpoints permission-guarded; received-invoices
gross VAT on all paths; orders-pdf custom-items authz.

Concurrency: $queryRaw SELECT...FOR UPDATE locks in ascending-id order (warehouse
confirm/cancel, attendance lockUserRow); uniqueness checks moved into create
transactions (TOCTOU -> 409); deterministic id tiebreak on second-precision
timestamp ordering (plan resolveCell/resolveGrid, warehouse FIFO).

Frontend: Rules-of-Hooks fixed across ~14 pages + PlanCellModal; UTC-date persisted
fields; dashboard invalidation gaps; stale-closure confirm bugs.

Tooling/tests: ESLint flat config (react-hooks/rules-of-hooks = error) + Prettier;
tsconfig.test.json so tsc -b type-checks the tests; removed 3 dead deps; npm audit
fix (8 -> 3). Suite 195 -> 247 (happy-path auth, FIFO oldest-first, flakiness fixes),
isolated on app_test via .env.test with a hard-throw setup guard.

Gates: tsc 0 | build 0 | vitest 247/247 | eslint 0 errors.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

eslint.config.mjs

@@ -0,0 +1,78 @@
+import js from "@eslint/js";
+import tseslint from "typescript-eslint";
+import reactHooks from "eslint-plugin-react-hooks";
+import reactRefresh from "eslint-plugin-react-refresh";
+import globals from "globals";
+import prettier from "eslint-config-prettier";
+
+export default tseslint.config(
+  {
+    ignores: [
+      "dist/**",
+      "dist-client/**",
+      "node_modules/**",
+      "prisma/migrations/**",
+      "src/admin/bones/**",
+      "*.config.js",
+      "*.config.mjs",
+      "*.config.ts",
+      ".claude/**",
+    ],
+  },
+  js.configs.recommended,
+  ...tseslint.configs.recommended,
+  {
+    // Server + shared code
+    files: ["src/**/*.{ts,tsx}", "scripts/**/*.ts", "prisma/seed.ts"],
+    languageOptions: {
+      globals: { ...globals.node, ...globals.browser },
+    },
+    rules: {
+      // TS already resolves identifiers — `no-undef` only false-positives on
+      // global types/ambient names in .ts files.
+      "no-undef": "off",
+      "@typescript-eslint/no-explicit-any": "warn",
+      "@typescript-eslint/no-unused-vars": [
+        "warn",
+        { argsIgnorePattern: "^_", varsIgnorePattern: "^_" },
+      ],
+      "@typescript-eslint/no-require-imports": "warn",
+      "no-empty": ["warn", { allowEmptyCatch: false }],
+      // Intentional control-character regexes (NUL/path-traversal guards,
+      // combining-marks stripping) — not a defect here.
+      "no-control-regex": "off",
+      // Stylistic / advisory — surface as warnings, don't fail the lint gate.
+      "no-useless-escape": "warn",
+      "no-useless-assignment": "warn",
+      "preserve-caught-error": "warn",
+      "prefer-const": "warn",
+    },
+  },
+  {
+    // Frontend React code
+    files: ["src/admin/**/*.{ts,tsx}", "src/**/*.tsx"],
+    plugins: {
+      "react-hooks": reactHooks,
+      "react-refresh": reactRefresh,
+    },
+    rules: {
+      "react-hooks/rules-of-hooks": "error",
+      "react-hooks/exhaustive-deps": "warn",
+    },
+  },
+  {
+    // Plain Node helper scripts (.js/.mjs/.cjs in scripts/)
+    files: ["scripts/**/*.{js,mjs,cjs}"],
+    languageOptions: { globals: { ...globals.node } },
+    rules: { "no-undef": "off" },
+  },
+  {
+    // Tests
+    files: ["src/__tests__/**/*.ts"],
+    languageOptions: { globals: { ...globals.node } },
+    rules: {
+      "@typescript-eslint/no-explicit-any": "off",
+    },
+  },
+  prettier,
+);