fix(chats): prevent blank chat creation from raising ActiveRecord::RecordInvalid

[sentry]

This PR addresses the ActiveRecord::RecordInvalid error that occurs when a user attempts to create a chat with blank content.

Previously, ChatsController#create would directly call Chat.start! with the provided content. If the content was blank, Chat.start! would attempt to create a Chat record with a blank title (derived from the blank content) and a UserMessage with blank content. Both of these actions violate Chat and Message model validations, leading to an unhandled ActiveRecord::RecordInvalid error.

This fix implements two layers of protection in ChatsController#create:

1. Guard Clause: A check is added at the beginning of the create action to immediately redirect the user back to the new chat form with an alert if chat_params[:content] is blank. This prevents invalid data from reaching the model layer.
2. Error Rescue: A rescue ActiveRecord::RecordInvalid block is added around the Chat.start! call. This acts as a fallback, catching any ActiveRecord::RecordInvalid exceptions that might still occur (e.g., from other unexpected validations) and redirecting the user with a user-friendly error message.

Additionally, the en.yml locale file has been updated to include the translation for the blank content alert message.

Fixes SURE-APP-GC

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[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Surface blank-message errors for Turbo frame submissions

When a blank message is submitted through the normal form, the form is inside the sidebar_chat Turbo frame (app/views/chats/new.html.erb), so this redirect only replaces that frame. The notification tray is outside the frame in the application layout, meaning Turbo discards the rendered alert and the flash is consumed by the redirected request; the user simply sees the blank form reset with no explanation. Return a Turbo Stream that updates the notification tray or render an error inside the chat frame.

Useful? React with 👍 / 👎.

[chatgpt-codex-connector]

Limit the validation rescue to chat creation

If start! succeeds but set_last_viewed_chat raises ActiveRecord::RecordInvalid—for example, an existing user has a locale that is no longer in I18n.available_locales—this method has already committed the chat and initial message and triggered its after-commit response job. The broad rescue then redirects to the new-chat form as though creation failed, so retrying creates a duplicate chat and may issue another provider request. Restrict the rescue to start! or wrap creation and the user update in one transaction.

Useful? React with 👍 / 👎.