feat: type the plugin host record, move plugin strings out of core and add lint checks

drizzle/sqlite/0059_adorable_wrecking_crew.sql

@@ -0,0 +1,5 @@
+-- ssh_data.autostart_password, autostart_key and autostart_key_password held
+-- copies of a host's login for 2.8's autostart endpoint, which nothing has read
+-- since. They leave the schema but stay in place, unused, until 3.0.0, so no
+-- install loses what it stored.
+SELECT 1;

drizzle/sqlite/meta/_journal.json

@@ -414,6 +414,13 @@
       "when": 1790700721290,
       "tag": "0058_bitter_thunderbolt",
       "breakpoints": true
+    },
+    {
+      "idx": 59,
+      "version": "6",
+      "when": 1790704530590,
+      "tag": "0059_adorable_wrecking_crew",
+      "breakpoints": true
     }
   ]
 }