Fix schema dump crash on FTS5 virtual tables

ActiveRecord 8.0.3's Ruby schema dumper crashes on SQLite FTS5 tables.
Switch to SQL schema format so db:schema:dump uses sqlite3 directly.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: inutano

Rakefile

@@ -2,6 +2,9 @@ ENV["SKIP_APP_CONFIGURE"] = "1"
 require 'sinatra/activerecord/rake'
 require './app'
 
+# Use SQL schema format to support SQLite FTS5 virtual tables
+ActiveRecord.schema_format = :sql
+
 PROJ_ROOT = File.expand_path(__dir__)
 
 Dir["#{PROJ_ROOT}/lib/tasks/**/*.rake"].each do |path|