feat(ollama): enforce JSON logits & add nvim_buffer edit action

- Added format parameter to Ollama generate for JSON logit enforcement.

- Implemented safe edit action in nvim_buffer MCP tool to replace raw Lua.

server/src/lib.rs

@@ -308,6 +308,7 @@ pub async fn memory_consolidation_worker(state: Arc<MemoryState>) {
                 &prompt,
                 None,
                 Some("You are a helpful JSON-only data deduplication assistant. Output only JSON."),
+                Some("json"),
             )
             .await
         {