fix: unified scraper temp config uses unified format for doc_scraper (#317)

The unified scraper's _scrape_documentation() was creating temp configs
in flat/legacy format (no "sources" key), causing doc_scraper's
ConfigValidator to reject them. Wrap the temp config in unified format
with a "sources" array. Also remove dead code branches and fix a
pre-existing test that didn't clear GITHUB_TOKEN from env.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tests/test_unified_scraper_orchestration.py

@@ -224,7 +224,11 @@ class TestScrapeDocumentation:
             mock_run.return_value = MagicMock(returncode=1, stdout="", stderr="")
             scraper._scrape_documentation(source)
 
-        assert any("llms_txt_url" in c for c in written_configs)
+        assert any(
+            "llms_txt_url" in s
+            for c in written_configs
+            for s in c.get("sources", [c])
+        )
 
     def test_start_urls_forwarded_to_doc_config(self, tmp_path):
         """start_urls from source is forwarded to the temporary doc config."""
@@ -247,7 +251,11 @@ class TestScrapeDocumentation:
             mock_run.return_value = MagicMock(returncode=1, stdout="", stderr="")
             scraper._scrape_documentation(source)
 
-        assert any("start_urls" in c for c in written_configs)
+        assert any(
+            "start_urls" in s
+            for c in written_configs
+            for s in c.get("sources", [c])
+        )
 
 
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