fix(jobnet-search): emit source: search-fallback on stdout for external ads (#549) (#550)

* fix(jobnet-search): emit source: search-fallback on stdout for external ads (#549)

Move the degraded search summary signal from stderr to stdout as a source: search-fallback field on DetailApiResponse. Keeps stderr quiet on success across all portal CLIs, renders the degraded signal in plain and table format outputs, documents the optional field in the CLI README, and covers the fallback execution path with tests.

* changelog: place the #550 entry under [Unreleased]

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Mads Lorentzen <madslorentzen_17@hotmail.com>
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

.agents/skills/jobnet-search/cli/tests/detail-formatting.test.ts

@@ -92,6 +92,14 @@ describe("formatDetailPlain", () => {
     expect(formatted).toContain("Deadline: -");
     expect(formatted).not.toContain("Apply:");
   });
+
+  test("renders source fallback warning line when source is present and omits it when absent", () => {
+    const directFormatted = formatDetailPlain(detail());
+    expect(directFormatted).not.toContain("Source:");
+
+    const fallbackFormatted = formatDetailPlain(detail({ source: "search-fallback" }));
+    expect(fallbackFormatted).toContain("Source: search-fallback (detail unavailable, synthesised from search)");
+  });
 });