Upgrade config.load_defaults from 5.2 to 8.0

Migrates Rails configuration defaults to match Rails 8.1 runtime.
This enables modern security and performance features:

- Same-site cookies and secure cookie metadata
- belongs_to associations require presence by default
- SHA256 for key derivation and HMAC
- Query log tags for debugging
- Regexp timeout (ReDoS protection)
- Strict HTTP freshness checking

Removes deprecated to_time_preserves_timezone setting (now default).

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: etewiah

config/application.rb

@@ -22,16 +22,14 @@
 
 module StandalonePwb
   class Application < Rails::Application
-    # Initialize configuration defaults for originally generated Rails version.
-    config.load_defaults 5.2
+    # Initialize configuration defaults for Rails 8.0
+    # Migrated from 5.2 - see config/initializers/new_framework_defaults_migration.rb
+    config.load_defaults 8.0
 
     # Enable gzip compression for all responses (HTML, CSS, JS, JSON)
     # This significantly reduces transfer sizes and improves page load times
     config.middleware.use Rack::Deflater
 
-    # Opt in to Rails 8.1 timezone behavior
-    config.active_support.to_time_preserves_timezone = :zone
-
     # Please, add to the `ignore` list any other `lib` subdirectories that do
     # not contain `.rb` files, or that should not be reloaded or eager loaded.
     # Common ones are `templates`, `generators`, or `middleware`, for example.