enh: adjust instance defaults migration

src/instance-app/migrations/1699198734_pockethost_defaults.js

@@ -0,0 +1,38 @@
+migrate(
+  (db) => {
+    try {
+      const APP_DEFAULTS = {
+        appName: 'Acme',
+        appUrl: 'http://localhost:8090',
+        senderName: 'Support',
+        senderAddress: 'support@example.com',
+      }
+
+      const { PH_APP_NAME, PH_INSTANCE_URL, PH_APEX_DOMAIN } = process.env
+
+      const dao = new Dao(db)
+
+      const settings = dao.findSettings()
+      if (!settings) {
+        throw new Error(`Expected settings here`)
+      }
+
+      const fix = (field, newValue) => {
+        if (!newValue || settings.meta[field] !== APP_DEFAULTS[field]) return
+        settings.meta[field] = newValue
+      }
+      const { hostname } = new URL(PH_INSTANCE_URL)
+      fix(`appName`, PH_APP_NAME)
+      fix(`appUrl`, PH_INSTANCE_URL)
+      fix(`senderName`, PH_APP_NAME)
+      fix(`senderAddress`, `${PH_APP_NAME}@${hostname}`)
+
+      dao.saveSettings(settings)
+    } catch (e) {
+      console.error(`***error applying defaults: ${e}`)
+    }
+  },
+  (db) => {
+    // add down queries...
+  },
+)