add reload_association to documentation

Deprecate support of older `config.ru`

Support content_type in AzureStorageService#url

* Add migrations per rails engine conventions

* Fix failing tests

Add in the content_type option, which is defined as part of the generic
ActiveStorage::Service class.

Without this option, attempts to generate a URL for an attached file
fail with "ArgumentError (unknown keyword: content_type)"

[ci skip] Update action_mailer_basics.md

In some examples and guides we are recommending to use code like:

```ruby
verified_user = User.find_by(id: cookies.signed[:user_id])
```

My suggestion is to use instead:

```ruby
verified_user = User.find_by(id: cookies.encrypted[:user_id])
```

which invites users to prefer the "newer" encrypted cookies over the
"legacy" signed cookies.

Since Rails 4.0, `config.ru` generated by default uses instances of
`Rails.application`.  Therefore, I think that it is good to deprecate
the old behavior.

Related: #9669

* Extend image_tag to accept ActiveStorage's Attachments and Variants

* Flip resolve_image_source around

* Add tests for the new use-cases of image_tag

* Remove the higher-level test

* Update image_tag documentation

* Add error states into the test suite

* Re-raise polymorhic_url's NoMethodError as ArgumentError

* delegate_missing_to will raise DelegationError instead of NoMethodError

Should _probably_ be done across the board with all of our
documentation, but going to leave that for another time :)

[ci skip]

[ci skip]

Light grammar edits.

[ci skip]

Light grammar edits.

[ci skip]

Light grammar fixes, and added a few backticks.

[ci skip]

Fixes a few grammar things.

[ci skip]

Postgres --> PostgreSQL
ActionCable --> Action Cable

[ci skip]

Fix wrong service name in the storage.yml

Merge pull request #30099 from bogdanvlviv/set_version_of_active_storage_to_5_2_0_alpha_inside_package_json

Active Storage to 5.2.0.alpha inside `activestorage/package.json`

Follow #30083

Replaces the 17 for the actual call to params[:id] that would make th…

Replaces the 17 for the actual call to params[:id] that would make the code work as intended. [ci skip]

Remove outdated comment [ci skip]

The comment was describing a previous version of the method with
a different signature. This is outdated since e76c38ef

`module ActiveStorage`, not `ActiveStorage::Class`

Use `content_type.start_with?("...")` than `content_type =~ /^.../`

Fix ruby warnings

Active Storage: check for `app.secrets.secret_key_base`, not `app.config.secret_key_base`

Add missing blank line between `config.active_storage` and `config.action_cable`

Change gem version of Active Storage to 5.2.0.alpha

By default, apps only have the former set.

Remove unnecessary variable

It was right as originally written in #15440.