feat: Add seed file for mission metadata

- Create missions from scenario directories
- Auto-discover scenarios in app/assets/scenarios/
- Simple metadata only (no scenario data in DB)
- Scenario data generated on-demand via ERB

db/seeds.rb

@@ -0,0 +1,25 @@
+puts "Creating BreakEscape missions..."
+
+# List all scenario directories
+scenario_dirs = Dir.glob(Rails.root.join('app/assets/scenarios/*')).select { |f| File.directory?(f) }
+
+scenario_dirs.each do |dir|
+  scenario_name = File.basename(dir)
+  next if scenario_name == 'common'  # Skip common directory if it exists
+
+  # Create mission metadata
+  mission = BreakEscape::Mission.find_or_initialize_by(name: scenario_name)
+
+  if mission.new_record?
+    mission.display_name = scenario_name.titleize
+    mission.description = "Play the #{scenario_name.titleize} scenario"
+    mission.published = true
+    mission.difficulty_level = 3  # Default, can be updated later
+    mission.save!
+    puts "  ✓ Created: #{mission.display_name}"
+  else
+    puts "  - Exists: #{mission.display_name}"
+  end
+end
+
+puts "Done! Created #{BreakEscape::Mission.count} missions."