Add Ollama provider, portable memory, cultivation digest, refugee importer, GLM-OCR spike

- P0: unified soul binary with engram_node_full fix, read-back-verify, search fix
- P0: move API keys from plaintext plists to macOS Keychain
- P0: fix MCP backend URL (port 8742 → 7770)
- P1.6: memory-export/import scripts (AES-256-CBC, versioned .neuronmem format)
- P1.7: nightly cultivation digest with sharpness metric (launchd at 23:55)
- P2.10: Ollama provider in agentic loop (SOUL_LLM_PROVIDER=ollama)
- P3.12: refugee importer for ChatGPT/Screenpipe/generic formats
- P3.13: GLM-OCR spike — SHIP IT (mlx-vlm, 1.59GB, photo-to-memory.sh)

dist/neuron-api.c

@@ -180,7 +180,7 @@ el_val_t api_persisted(el_val_t id) {
     return 0;
   }
   el_val_t node = engram_get_node_json(id);
-  return (!str_eq(node, EL_STR("")) && !str_eq(node, EL_STR("null")));
+  return ((!str_eq(node, EL_STR("")) && !str_eq(node, EL_STR("null"))) && !str_eq(node, EL_STR("{}")));
   return 0;
 }