docs(demo): expand seed success message to cover embedded + server modes

Previously the final print in 00_seed_data.ipynb only told users to reuse
COORDINODE_ADDR, which is misleading for the default embedded workflow.
Now lists both paths: open sibling notebooks against the same
COORDINODE_EMBEDDED_PATH file, or point them at the same running server
via COORDINODE_ADDR.

Author: polaz

demo/notebooks/00_seed_data.ipynb

@@ -455,7 +455,9 @@
     "    print(f\"  \u2192 {r['dependency']}\")\n",
     "\n",
     "print(\"\\n\u2713 Demo data seeded.\")\n",
-    "print(\"To query it from notebooks 01\u201303, connect them to the same CoordiNode server (COORDINODE_ADDR).\")\n",
+    "print(\"To query it from notebooks 01\u201303:\")\n",
+    "print(\"  - Embedded mode: open them with the same COORDINODE_EMBEDDED_PATH (default /content/coordinode-demo.db in Colab, /tmp/coordinode-demo.db locally) \u2014 they will see this seeded graph.\")\n",
+    "print(\"  - Server mode: point them at the same running CoordiNode via COORDINODE_ADDR.\")\n",
     "client.close()"
    ]
   }