fix(jobnet-search): degrade a null publicationDate to a null date instead of crashing the search (#418) (#419)

date: job.publicationDate.slice(0, 10) trusted a TypeScript interface
claim nothing validates at runtime: apiFetch casts the JSON body, so one
ad with a null publication date threw TypeError inside the jobAds map
and the whole search exited 1 as API_ERROR. The neighboring
applicationDeadline field was already null-guarded with a 1900-01-01
sentinel. publicationDate is now typed nullable so the compiler enforces
the guard, and the ad degrades per-item to date: null. New test verified
to fail on the unfixed code with the exact production TypeError.

.agents/skills/jobnet-search/cli/src/commands/search.ts

@@ -18,7 +18,11 @@ export interface JobAdRaw {
   postalCode: number | null
   postalDistrictName: string | null
   country: string
-  publicationDate: string
+  // A TypeScript claim is not runtime validation: apiFetch casts the JSON
+  // body, so a null here arrives typed as string and .slice() throws,
+  // killing the whole search as API_ERROR (#418). Typed nullable so the
+  // compiler enforces the guard below.
+  publicationDate: string | null
   applicationDeadline: string | null
   applicationDeadlineStatus: string | null
   workHourPartTime: boolean
@@ -102,7 +106,7 @@ export function createSearchOutput(data: SearchApiResponse, flags: SearchFlags)
     isFavorite: job.isFavorite,
     company: job.hiringOrgName,
     location: job.postalDistrictName ?? job.municipality ?? null,
-    date: job.publicationDate.slice(0, 10),
+    date: job.publicationDate ? job.publicationDate.slice(0, 10) : null,
     deadline: job.applicationDeadline && !job.applicationDeadline.startsWith("1900-01-01")
       ? job.applicationDeadline.slice(0, 10)
       : null,
@@ -211,7 +215,7 @@ type JobAdResult = {
   occupation: string | null
   municipality: string | null
   postalCode: number | null
-  publicationDate: string
+  publicationDate: string | null
   applicationDeadline: string | null
 }