chore: ensure default org always exists (#12412)

* chore: ensure default org always exists

First user just joins the org created by the migration

coderd/database/migrations/000198_ensure_default_org.down.sql

@@ -0,0 +1 @@
+-- There is no down. If the org is created, just let it be. Deleting an org feels dangerous in a migration.

coderd/database/migrations/000198_ensure_default_org.up.sql

@@ -0,0 +1,16 @@
+-- This ensures a default organization always exists.
+INSERT INTO
+	organizations(id, name, description, created_at, updated_at, is_default)
+SELECT
+	-- Avoid calling it "default" as we are reserving that word as a keyword to fetch
+	-- the default org regardless of the name.
+	gen_random_uuid(),
+	'first-organization',
+	'Builtin default organization.',
+	now(),
+	now(),
+	true
+WHERE
+	-- Only insert if no organizations exist.
+	NOT EXISTS (SELECT * FROM organizations);
+