## Description
The widget conversation transcript endpoint (`POST
/api/v1/widget/conversations/transcript`) has no rate limit. Every other
comparable endpoint does: the agent-facing transcript API and the widget
conversation-create and contact-update endpoints are all throttled. This
gap lets a single client trigger a large burst of transcript emails from
one conversation.
This adds an IP-based throttle (5 requests/hour) for the endpoint,
placed inside the existing widget-API throttle block so it inherits the
`ENABLE_RACK_ATTACK_WIDGET_API` opt-out used by embedded/iframe clients.
The limit is generous for legitimate use (a visitor emailing themselves
a transcript) while stopping abusive loops. Throttled requests get the
standard 429 the widget already handles.
## Type of change
- [x] Bug fix (non-breaking change which fixes an issue)
## How Has This Been Tested?
`config/initializers/rack_attack.rb` throttles have no existing specs in
this file, so this follows the established convention (no new spec).
Verified `ruby -c` and `rubocop` pass on the file. The new throttle
mirrors the sibling widget throttles directly above it (same IP key,
path guard, and structure).
## Checklist:
- [x] My code follows the style guidelines of this project
- [x] I have performed a self-review of my code
- [x] My changes generate no new warnings
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Co-authored-by: Sojan Jose <sojan@pepalo.com>
