fix(cli): reject negative and fractional filter flags in Danish portal CLIs (#281)

Follow-up to #191: it tightened page/limit/per-page, but five filter flags still used bare z.coerce.number() and accepted negative and fractional values that were sent raw to the portals (e.g. --jobage=-5, --radius=2.5).

jobindex --jobage, jobnet --radius, jobdanmark --category/--jobtitle-id and jobbank --company now use .int().min(1), mirroring #191. Adds 8 network-free regression tests (a negative and a fractional case per flag) using the same validation-error pattern as the existing cli-flag-validation suites.

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

@@ -155,7 +155,7 @@ export const search = defineCommand({
     "postal-code": option(z.string().optional(), {
       description: "Postal code for radius search",
     }),
-    radius: option(z.coerce.number().default(50), {
+    radius: option(z.coerce.number().int().min(1).default(50), {
       description: "Radius in km from postal code",
     }),
     "occupation-area": option(z.string().optional(), {