Phase 22: SearXNG web research pipeline + settings layout overhaul

Research pipeline (research_topic tool):
- New service: services/research.py — sub-query generation, SearXNG
  search, URL fetch, deduplication, and LLM synthesis into a note
- 5 sub-queries × 3 pages = up to 15 sources, capped at 12 for synthesis
- Synthesis uses num_ctx=16384 + max_tokens=8192 for long-form output
- Prompt demands 2500+ words, 6+ topic-appropriate sections, detailed prose
- 429 retry with backoff; 1s inter-query sleep; raw_decode JSON parsing

search_web tool (new):
- Lightweight single-query SearXNG search, results returned inline in chat
- LLM answers conversationally in round 1; no note created
- web_search result type with external links in ToolCallCard

Infrastructure:
- llm.py: generate_completion accepts num_ctx override
- config.py: SEARXNG_URL + Config.searxng_enabled()
- docker-compose: OLLAMA_NUM_PARALLEL=2, commented SEARXNG_URL example
- intent.py: search_web and research_topic routing rules

Settings UI:
- 2-column grid layout (small sections pair up, complex span full width)
- Search Test section: live SearXNG query with result preview
- GET /api/settings/search?q= proxy endpoint
- Research button (magnifier) in ChatView input toolbar → popover modal

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

src/fabledassistant/routes/settings.py

@@ -84,3 +84,17 @@ async def test_caldav():
     uid = get_current_user_id()
     result = await test_connection(uid)
     return jsonify(result)
+
+
+@settings_bp.route("/search", methods=["GET"])
+@login_required
+async def test_search():
+    """Test SearXNG connectivity and preview results for a query."""
+    if not Config.searxng_enabled():
+        return jsonify({"configured": False, "results": [], "searxng_url": ""})
+    q = request.args.get("q", "").strip()
+    if not q:
+        return jsonify({"configured": True, "results": [], "searxng_url": Config.SEARXNG_URL})
+    from fabledassistant.services.research import _search_searxng
+    results = await _search_searxng(q)
+    return jsonify({"configured": True, "results": results, "query": q, "searxng_url": Config.SEARXNG_URL})