fix(phase3): description optional, restore nginx to host IP

- Make ledger description field optional (was required, caused 400)
- Revert nginx.conf back to 192.168.1.14:8090 (host IP, reliable)
- Keep docker-compose port mapping as 8090:8090
- Add $autoCancel:false to ledger/asset API calls

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

backend/pb_migrations/1776515455_updated_ledgers.js

@@ -0,0 +1,44 @@
+/// <reference path="../pb_data/types.d.ts" />
+migrate((db) => {
+  const dao = new Dao(db)
+  const collection = dao.findCollectionByNameOrId("ledgers_col")
+
+  // update
+  collection.schema.addField(new SchemaField({
+    "system": false,
+    "id": "lgr_desc",
+    "name": "description",
+    "type": "text",
+    "required": false,
+    "presentable": false,
+    "unique": false,
+    "options": {
+      "min": null,
+      "max": 500,
+      "pattern": ""
+    }
+  }))
+
+  return dao.saveCollection(collection)
+}, (db) => {
+  const dao = new Dao(db)
+  const collection = dao.findCollectionByNameOrId("ledgers_col")
+
+  // update
+  collection.schema.addField(new SchemaField({
+    "system": false,
+    "id": "lgr_desc",
+    "name": "description",
+    "type": "text",
+    "required": true,
+    "presentable": false,
+    "unique": false,
+    "options": {
+      "min": null,
+      "max": 500,
+      "pattern": ""
+    }
+  }))
+
+  return dao.saveCollection(collection)
+})