Drop SearXNG references: use built-in web_search

ARCHITECTURE.md

@@ -96,7 +96,7 @@ agent's experience, atoms are curated facts.
 | `outbox_sync.py` | CDC: PostgreSQL outbox → Qdrant and Memgraph |
 | `dedup.py` | semantic deduplication by embedding cosine (threshold 0.90) |
 | `verify.py` | self-critique (LLM verdict) + cross-confirmation (multiple sources) |
-| `research.py` | gap-filling loop: SearXNG search → ingest → commit |
+| `research.py` | gap-filling loop: web search → ingest → commit |
 | `code_symbols.py` | tree-sitter symbol extraction |
 | `code_graph.py` | tree-sitter dependency extraction (calls/imports/inherits) |
 | `inference.py` | forward-chaining logical rules over the graph until fixpoint |
@@ -124,7 +124,7 @@ source (text|pdf|epub|web)
 ```
 memory_stats / memory_list_gaps  → detect gap
 memory_add_gap(question)         → register
-SearXNG search                   → URLs
+web_search                       → URLs
 memory_ingest(url)               → atoms   (full page; snippet fallback if blocked)
 memory_verify                    → cross-confirm → verified
 ```