Drop SearXNG references: use built-in web_search

EXAMPLES.md

@@ -92,7 +92,7 @@ If nothing is found → say "not in the knowledge base" and offer to research it
 2. memory_add_gap("How does HNSW work?",
                   reason = "low_coverage", priority = 0.8)
 3. memory_research("How does HNSW indexing work?")
-                                    → searches SearXNG, ingests sources,
+                                    → searches the web, ingests sources,
                                       distills atoms, saves them
 4. memory_verify()                  → cross-confirm the new atoms
 5. memory_search("HNSW")            → now returns verified hits