fix(types): unblock catch-all routes under stricter Next 15.5 typing + Phase 2B deps

Two changes bundled (build was failing on the type fix; deps came along
on the same branch).

1. RouteHandler / withAuth / withPermission are now generic over the
   route's params shape. Default stays `Record<string, string>` for the
   common `[id]`-style routes (no caller changes needed). Catch-all
   routes like `[...path]` declare their narrow shape via a type-arg:

       export const PATCH = withAuth<{ path: string[] }>(
         withPermission<{ path: string[] }>('files', 'manage_folders',
           async (req, ctx, params) => { /* params.path: string[] */ }
         ),
       );

   Without this, Next.js 15.5+'s stricter route-type checking rejected
   the build because the inferred `params: Promise<{ path: string[] }>`
   for `[...path]` doesn't satisfy `Promise<Record<string, string>>`.

   Updated `src/app/api/v1/files/folders/[...path]/route.ts` (the only
   catch-all in the tree right now) to use the new generic.

2. Phase 2B deps (within-major-jump where the API didn't actually break):
   - @pdfme/common, @pdfme/generator, @pdfme/schemas: 5.5.10 → 6.1.2
     (closes 3 mod XSS/SSRF/decompression-bomb advisories)
   - lucide-react: 0.460.0 → 1.14.0
   - sonner: 1.7.4 → 2.0.7
   - tailwind-merge: 2.6.1 → 3.5.0

Tests: 1185/1185 vitest. tsc clean. Local `next build` succeeds.

Reverted (deferred to a focused PR):
- @hookform/resolvers 5: Resolver<T> typing change requires per-form
  useForm migration
- eslint 10: incompatible with @rushstack/eslint-patch (pulled in by
  eslint-config-next)
- react-day-picker 10: ClassNames removed `table`; needs calendar.tsx
  migration
- zod 4: 94 type errors cascading through drizzle insert types; needs
  comprehensive migration

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/lib/api/helpers.ts

@@ -44,11 +44,18 @@ export interface AuthContext {
   userAgent: string;
 }
 
-export type RouteHandler<T = unknown> = (
-  req: NextRequest,
-  ctx: AuthContext,
-  params: Record<string, string>,
-) => Promise<NextResponse<T>>;
+/**
+ * Route params type. Defaults to `Record<string, string>` for the common
+ * `[id]`-style routes. Catch-all routes (`[...slug]`) need to override
+ * `TParams` so Next.js 15.5+'s stricter route-type checking accepts the
+ * exported handler against the inferred `{ slug: string[] }` shape.
+ */
+export type RouteParams = Record<string, string | string[]>;
+
+export type RouteHandler<
+  TParams extends RouteParams = Record<string, string>,
+  T = unknown,
+> = (req: NextRequest, ctx: AuthContext, params: TParams) => Promise<NextResponse<T>>;
 
 // ─── deepMerge ───────────────────────────────────────────────────────────────
 
@@ -95,11 +102,11 @@ export function deepMerge(
  * export const POST = withAuth(withPermission('clients', 'create', handler));
  * ```
  */
-export function withAuth(
-  handler: RouteHandler,
+export function withAuth<TParams extends RouteParams = Record<string, string>>(
+  handler: RouteHandler<TParams>,
 ): (
   req: NextRequest,
-  routeContext: { params: Promise<Record<string, string>> },
+  routeContext: { params: Promise<TParams> },
 ) => Promise<NextResponse> {
   return async (req, routeContext) => {
     // Mint or accept a request id BEFORE entering the ALS frame so every
@@ -286,11 +293,11 @@ export function requireSuperAdmin(ctx: AuthContext, attemptedAction = 'super_adm
  * export const DELETE = withAuth(withPermission('clients', 'delete', handler));
  * ```
  */
-export function withPermission(
+export function withPermission<TParams extends RouteParams = Record<string, string>>(
   resource: keyof RolePermissions,
   action: string,
-  handler: RouteHandler,
-): RouteHandler {
+  handler: RouteHandler<TParams>,
+): RouteHandler<TParams> {
   return async (req, ctx, params) => {
     if (!ctx.isSuperAdmin) {
       const resourcePerms = ctx.permissions?.[resource] as Record<string, boolean> | undefined;