style: Run ruff format on 15 files (CI fix)

CI uses 'ruff format' not 'black' - applied proper formatting:

Files reformatted by ruff:
- config_extractor.py
- doc_scraper.py
- how_to_guide_builder.py
- llms_txt_parser.py
- pattern_recognizer.py
- test_example_extractor.py
- unified_codebase_analyzer.py
- test_architecture_scenarios.py
- test_async_scraping.py
- test_github_scraper.py
- test_guide_enhancer.py
- test_install_agent.py
- test_issue_219_e2e.py
- test_llms_txt_downloader.py
- test_skip_llms_txt.py

Fixes CI formatting check failure.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/skill_seekers/cli/llms_txt_parser.py

@@ -127,9 +127,7 @@ class LlmsTxtParser:
         # Extract code blocks
         code_blocks = re.findall(r"```(\w+)?\n(.*?)```", content, re.DOTALL)
         for lang, code in code_blocks:
-            page["code_samples"].append(
-                {"code": code.strip(), "language": lang or "unknown"}
-            )
+            page["code_samples"].append({"code": code.strip(), "language": lang or "unknown"})
 
         # Extract h2/h3 headings
         headings = re.findall(r"^(#{2,3})\s+(.+)$", content, re.MULTILINE)
@@ -146,9 +144,7 @@ class LlmsTxtParser:
         content_no_code = re.sub(r"```.*?```", "", content, flags=re.DOTALL)
 
         # Extract paragraphs
-        paragraphs = [
-            p.strip() for p in content_no_code.split("\n\n") if len(p.strip()) > 20
-        ]
+        paragraphs = [p.strip() for p in content_no_code.split("\n\n") if len(p.strip()) > 20]
         page["content"] = "\n\n".join(paragraphs)
 
         return page