feat: add Wikipedia as research pipeline source alongside SearXNG

Runs wiki_search in parallel with SearXNG queries; Wikipedia results
(which already carry content via their extract field) are merged into
the source pool before outline generation, skipping a separate fetch
step. Also fixes a pre-existing F811 ruff violation in the test file.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/fabledassistant/services/research.py

@@ -10,6 +10,7 @@ import httpx
 from fabledassistant.config import Config
 from fabledassistant.services.llm import fetch_url_content, generate_completion, stream_chat
 from fabledassistant.services.notes import create_note, update_note
+from fabledassistant.services.wikipedia import wiki_search
 from fabledassistant.models.note import Note
 
 logger = logging.getLogger(__name__)
@@ -205,7 +206,7 @@ async def run_research_pipeline(
     queries = await _generate_sub_queries(topic, model)
     logger.info("Research: generated %d sub-queries for topic '%s'", len(queries), topic)
 
-    # Step 2: Search all queries in parallel (200 ms stagger to avoid hammering SearXNG)
+    # Step 2: Search all queries in parallel (SearXNG + Wikipedia)
     async def _search_with_stagger(i: int, query: str) -> tuple[str, list[dict]]:
         if i > 0:
             await asyncio.sleep(0.2 * i)
@@ -214,13 +215,22 @@ async def run_research_pipeline(
         logger.info("Research: query '%s' → %d results", query, len(results))
         return query, results
 
-    search_results = await asyncio.gather(
+    async def _wiki_for_query(query: str) -> list[dict]:
+        return await wiki_search(query, limit=1)
+
+    searxng_task = asyncio.gather(
         *[_search_with_stagger(i, q) for i, q in enumerate(queries)]
     )
+    wiki_task = asyncio.gather(
+        *[_wiki_for_query(q) for q in queries]
+    )
+    search_results, wiki_results = await asyncio.gather(searxng_task, wiki_task)
 
     # Deduplicate URLs across all queries
     seen_urls: set[str] = set()
     url_tasks: list[tuple[str, dict, str]] = []  # (url, result_dict, query)
+    wiki_sources: list[dict] = []  # Wikipedia articles (already have content)
+
     for query, results in search_results:
         for result in results[:PAGES_PER_QUERY]:
             url = result.get("url", "")
@@ -228,7 +238,21 @@ async def run_research_pipeline(
                 seen_urls.add(url)
                 url_tasks.append((url, result, query))
 
-    # Fetch all unique URLs in parallel
+    # Add Wikipedia results (they already have content via extract)
+    for query, wiki_hits in zip(queries, wiki_results):
+        for hit in wiki_hits:
+            url = hit.get("url", "")
+            if url and url not in seen_urls:
+                seen_urls.add(url)
+                wiki_sources.append({
+                    "url": url,
+                    "title": hit["title"],
+                    "query": query,
+                    "snippet": hit["extract"][:200],
+                    "content": hit["extract"],
+                })
+
+    # Fetch all unique SearXNG URLs in parallel
     async def _fetch_source(url: str, result: dict, query: str) -> dict:
         title = result.get("title", url)
         _status(f"Reading: {title[:60]}...")
@@ -241,10 +265,12 @@ async def run_research_pipeline(
             "content": content,
         }
 
-    all_sources: list[dict] = list(await asyncio.gather(
+    fetched_sources: list[dict] = list(await asyncio.gather(
         *[_fetch_source(url, result, query) for url, result, query in url_tasks]
     ))
 
+    all_sources = wiki_sources + fetched_sources
+
     if not all_sources:
         raise ValueError(f"No results found for '{topic}'")