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/config.py

@@ -56,6 +56,13 @@ class Config:
     OIDC_SCOPES: str = os.environ.get("OIDC_SCOPES", "openid profile email")
     LOCAL_AUTH_ENABLED: bool = os.environ.get("LOCAL_AUTH_ENABLED", "true").lower() not in ("0", "false", "no")
 
+    # SearXNG web search (external instance)
+    SEARXNG_URL: str = os.environ.get("SEARXNG_URL", "")
+
     @classmethod
     def oidc_enabled(cls) -> bool:
         return bool(cls.OIDC_ISSUER and cls.OIDC_CLIENT_ID and cls.OIDC_CLIENT_SECRET)
+
+    @classmethod
+    def searxng_enabled(cls) -> bool:
+        return bool(cls.SEARXNG_URL)