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>

src/schemas/plan.schema.ts

@@ -1,13 +1,9 @@
 import { z } from "zod";
+import { intIdFromForm, isoDateString, nullableNumberFromForm } from "./common";
 
-const isoDate = z
-  .string()
-  .regex(/^\d{4}-\d{2}-\d{2}$/, "Datum musí být ve formátu YYYY-MM-DD");
+const isoDate = isoDateString;
 
-const intFromForm = z
-  .union([z.number(), z.string()])
-  .transform((v) => Number(v))
-  .refine((n) => Number.isInteger(n) && n > 0, "Neplatné ID");
+const intFromForm = intIdFromForm;
 
 // Category is now a dynamic key (validated against plan_categories in the
 // service). Keep it a non-empty string here.
@@ -18,10 +14,7 @@ export const CreatePlanEntrySchema = z
     user_id: intFromForm,
     date_from: isoDate,
     date_to: isoDate,
-    project_id: z
-      .union([z.number(), z.string()])
-      .transform((v) => Number(v))
-      .nullish(),
+    project_id: nullableNumberFromForm.nullish(),
     category: planCategoryEnum.default("work"),
     note: z.string().max(500, "Maximálně 500 znaků"),
   })
@@ -34,10 +27,7 @@ export const UpdatePlanEntrySchema = z
   .object({
     date_from: isoDate.optional(),
     date_to: isoDate.optional(),
-    project_id: z
-      .union([z.number(), z.string(), z.null()])
-      .transform((v) => (v === null ? null : Number(v)))
-      .nullish(),
+    project_id: nullableNumberFromForm.nullish(),
     category: planCategoryEnum.optional(),
     note: z.string().max(500).optional(),
   })
@@ -55,19 +45,13 @@ export const UpdatePlanEntrySchema = z
 export const CreatePlanOverrideSchema = z.object({
   user_id: intFromForm,
   shift_date: isoDate,
-  project_id: z
-    .union([z.number(), z.string()])
-    .transform((v) => Number(v))
-    .nullish(),
+  project_id: nullableNumberFromForm.nullish(),
   category: planCategoryEnum,
   note: z.string().max(500, "Maximálně 500 znaků"),
 });
 
 export const UpdatePlanOverrideSchema = z.object({
-  project_id: z
-    .union([z.number(), z.string(), z.null()])
-    .transform((v) => (v === null ? null : Number(v)))
-    .nullish(),
+  project_id: nullableNumberFromForm.nullish(),
   category: planCategoryEnum.optional(),
   note: z.string().max(500).optional(),
 });
@@ -96,10 +80,7 @@ export const BulkPlanEntrySchema = z
       .union([z.boolean(), z.string()])
       .transform((v) => v === true || v === "true" || v === "1")
       .default(false),
-    project_id: z
-      .union([z.number(), z.string(), z.null()])
-      .transform((v) => (v === null ? null : Number(v)))
-      .nullish(),
+    project_id: nullableNumberFromForm.nullish(),
     category: planCategoryEnum.default("work"),
     note: z.string().max(500, "Maximálně 500 znaků").default(""),
   })