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>

docker-compose.yml

@@ -13,6 +13,8 @@ services:
       OLLAMA_URL: "http://ollama:11434"
       OLLAMA_MODEL: "${OLLAMA_MODEL:-llama3.1}"
       SECRET_KEY: "${SECRET_KEY:-dev-secret-change-me}"
+      # Uncomment and set to enable web research via SearXNG:
+      # SEARXNG_URL: "http://searxng:8080"
     healthcheck:
       test: ["CMD", "python", "-c", "import urllib.request; urllib.request.urlopen('http://localhost:5000/api/health')"]
       interval: 10s
@@ -40,6 +42,7 @@ services:
       - ollama_models:/root/.ollama
     environment:
       OLLAMA_MAX_LOADED_MODELS: "2"
+      OLLAMA_NUM_PARALLEL: "2"
       OLLAMA_KEEP_ALIVE: "30m"
       OLLAMA_FLASH_ATTENTION: "1"
     deploy: