chore: upgrade Zod 4, Vitest 4, and TypeScript 7

Bump major tooling stacks and adapt Zod error APIs (issues/flattenError) plus tsconfig paths for TS 7 baseUrl removal.

Co-authored-by: Cursor <[email protected]>

src/lib/foundation/action.ts

@@ -1,4 +1,4 @@
-import type { z } from "zod";
+import { z } from "zod";
 import { logAuthorizationEvent } from "@/lib/admin/authorization-events";
 import { auth } from "@/lib/auth";
 import { canAccess, getApiAdminContext } from "@/lib/permissions";
@@ -112,7 +112,10 @@ export function adminAction<TSchema extends z.ZodType | undefined = undefined>(
 					if (!parsed.success) {
 						return fail(
 							"Validation failed",
-							parsed.error.flatten().fieldErrors as Record<string, string[]>,
+							z.flattenError(parsed.error).fieldErrors as Record<
+								string,
+								string[]
+							>,
 						);
 					}
 					data = parsed.data;
@@ -188,7 +191,10 @@ export function authAction<TSchema extends z.ZodType | undefined = undefined>(
 					if (!parsed.success) {
 						return fail(
 							"Validation failed",
-							parsed.error.flatten().fieldErrors as Record<string, string[]>,
+							z.flattenError(parsed.error).fieldErrors as Record<
+								string,
+								string[]
+							>,
 						);
 					}
 					data = parsed.data;