Fixes https://linear.app/chatwoot/issue/CW-7559/inbox-limit-abuse
## Why
The regular inbox API checked limits in the controller, but WhatsApp
embedded signup creates inboxes through a service using `Inbox.create!`.
That let Enterprise account inbox limits be skipped for embedded signup.
## What this change does
- Adds an Inbox create-time validation hook in OSS and implements the
limit check in the Enterprise Inbox module.
- Removes the duplicate controller/helper limit check so the model is
the single enforcement point.
- Preserves the existing `402 Payment Required` API response for account
inbox limit failures.
- Keeps updates to existing inboxes allowed when an account is already
at its inbox limit.
## Validation
- `bundle exec rspec
spec/controllers/api/v1/accounts/inboxes_controller_spec.rb
spec/enterprise/models/inbox_spec.rb`
### Description
Inbound voice calls now route ownership cleanly: the call widget is
hidden from agents who aren't the conversation assignee, the first agent
to pick up becomes the assignee, and any later join attempt by another
agent is rejected with a clear "<agent> is already handling the call."
alert.
Closes
https://linear.app/chatwoot/issue/PLA-98/inbound-voice-calls-assignment-aware-visibility-auto-assignment-on
### How to test
1. As Agent A and Agent B, open the dashboard for the same voice inbox
in two browsers.
2. Place an inbound call to the inbox with the conversation
**unassigned** — both agents should see the call widget.
3. Have Agent A click **Join**. Agent A's widget transitions to the
active call; Agent B's widget disappears (conversation is now assigned
to Agent A).
4. While the call is in progress, attempt to join from a third agent
(e.g., via the bubble in the conversation timeline) — the join is
rejected with the toast `Agent A is already handling the call.`
5. Resolve the conversation, then place a second call to a conversation
that is already manually assigned to Agent A — only Agent A sees the
widget; nobody else does.
6. Race test: trigger two near-simultaneous join attempts (two agents
click Join within a few hundred ms of each other) — exactly one wins;
the other gets the conflict alert.
---------
Co-authored-by: Muhsin <12408980+muhsin-k@users.noreply.github.com>
- Initialize an "enterprise" folder that is copyrighted.
- You can remove this folder and the system will continue functioning normally, in case you want a purely MIT licensed product.
- Enable limit on the number of user accounts in enterprise code.
- Use enterprise edition injector methods (inspired from Gitlab).
- SaaS software would run enterprise edition software always.
Co-authored-by: Pranav Raj S <pranav@chatwoot.com>