Enforce column limits via concern

SQLite columns lengths are purely informational, so we'll enforce the
limits via a concern that checks the lengths from the schema.

config/initializers/table_definition_column_limits.rb

@@ -1,4 +1,4 @@
-# Apply MySQL-compatible column limits when using SQLite.
+# Apply MySQL-compatible column limits when defining tables.
 #
 # For string columns: defaults to 255 (MySQL's VARCHAR default)
 #
@@ -7,17 +7,19 @@
 #   - size: :tiny: 255 (TINYTEXT)
 #   - size: :medium: 16,777,215 (MEDIUMTEXT)
 #   - size: :long: 4,294,967,295 (LONGTEXT)
+#
+# This ensures the SQLite schema records the same limits as MySQL,
+# which the ColumnLimits validation concern uses to enforce limits.
 
 module TableDefinitionColumnLimits
-  # Map MySQL size options to limits
   TEXT_SIZE_TO_LIMIT = {
-    tiny: 255,             # TINYTEXT
-    medium: 16_777_215,    # MEDIUMTEXT
-    long: 4_294_967_295    # LONGTEXT
+    tiny: 255,
+    medium: 16_777_215,
+    long: 4_294_967_295
   }.freeze
 
-  TEXT_DEFAULT_LIMIT = 65_535   # TEXT
-  STRING_DEFAULT_LIMIT = 255    # VARCHAR
+  TEXT_DEFAULT_LIMIT = 65_535
+  STRING_DEFAULT_LIMIT = 255
 
   def column(name, type, **options)
     if type == :string
@@ -27,16 +29,11 @@ module TableDefinitionColumnLimits
     if type == :text
       if options.key?(:size)
         size = options.delete(:size)
-        options[:limit] = TEXT_SIZE_TO_LIMIT.fetch(size) do
+        options[:limit] ||= TEXT_SIZE_TO_LIMIT.fetch(size) do
           raise ArgumentError, "Unknown text size: #{size.inspect}. Use :tiny, :medium, or :long"
         end
-      elsif options.key?(:limit)
-        valid_limits = [TEXT_DEFAULT_LIMIT] + TEXT_SIZE_TO_LIMIT.values
-        unless valid_limits.include?(options[:limit])
-          raise ArgumentError, "Invalid limit #{options[:limit]} for text column. Use `size:` (:tiny, :medium, :long) or omit for default TEXT."
-        end
       else
-        options[:limit] = TEXT_DEFAULT_LIMIT
+        options[:limit] ||= TEXT_DEFAULT_LIMIT
       end
     end
 
@@ -47,3 +44,15 @@ end
 ActiveSupport.on_load(:active_record) do
   ActiveRecord::ConnectionAdapters::TableDefinition.prepend(TableDefinitionColumnLimits)
 end
+
+ActiveSupport.on_load(:action_text_rich_text) do
+  include ColumnLimits
+end
+
+ActiveSupport.on_load(:active_storage_blob) do
+  include ColumnLimits
+end
+
+ActiveSupport.on_load(:active_storage_attachment) do
+  include ColumnLimits
+end