Increase bootcamp code columns from TEXT to MEDIUMTEXT (#8489)

The `code` column on bootcamp_submissions, bootcamp_solutions, and
bootcamp_drawings used MySQL TEXT (64KB with utf8mb4), which is too
small for some user submissions. Upgrade to MEDIUMTEXT (16MB) to
prevent ActiveRecord::ValueTooLong errors.

Closes #8483

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: iHiD

db/migrate/20260209141203_increase_bootcamp_code_column_sizes.rb

@@ -0,0 +1,9 @@
+class IncreaseBootcampCodeColumnSizes < ActiveRecord::Migration[7.1]
+  def change
+    return if Rails.env.production?
+
+    change_column :bootcamp_submissions, :code, :text, size: :medium
+    change_column :bootcamp_solutions, :code, :text, size: :medium
+    change_column :bootcamp_drawings, :code, :text, size: :medium
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.1].define(version: 2025_12_11_055432) do
+ActiveRecord::Schema[7.1].define(version: 2026_02_09_141203) do
   create_table "active_storage_attachments", charset: "utf8mb4", collation: "utf8mb4_unicode_ci", force: :cascade do |t|
     t.string "name", null: false
     t.string "record_type", null: false
@@ -106,7 +106,7 @@
   create_table "bootcamp_drawings", charset: "utf8mb4", collation: "utf8mb4_unicode_ci", force: :cascade do |t|
     t.bigint "user_id", null: false
     t.string "uuid", null: false
-    t.text "code", null: false
+    t.text "code", size: :medium, null: false
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
     t.string "title", null: false
@@ -173,7 +173,7 @@
     t.bigint "user_id"
     t.bigint "exercise_id"
     t.string "uuid", null: false
-    t.text "code", null: false
+    t.text "code", size: :medium, null: false
     t.datetime "completed_at"
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
@@ -190,7 +190,7 @@
     t.string "uuid", null: false
     t.bigint "solution_id"
     t.integer "status", limit: 2, null: false
-    t.text "code", null: false
+    t.text "code", size: :medium, null: false
     t.text "readonly_ranges", null: false
     t.text "test_results", null: false
     t.datetime "created_at", null: false